Introductory Material

1. What are the 5 properties that define a living organism? energy, cells, info, replication,

evolution.

2. What is a theory? Explanation for a very general class of phenomena or observations.

3. What is a hypothesis? a proposed explanation.

4. Which two theories form the framework for modern biological science? Cell theory &

evolution by natural selection.

5. What are the two steps to hypothesis testing? State hypothesis and list predictions. Design

observational or experimental study to test predictions.

6. What is a control? Baseline for an experiment.

7. What was the control in the ant experiment? The normal ants.

8. What are the two main statements of the cell theory? All organisms are made of cells and all

cells come from pre-existing cells.

9. Who disproved spontaneous generation and demonstrated that cell theory was

correct? Louis Pasteur.

10. What is evolution? Characteristic change in a population over time. Species are related.

11. What is the mechanism by which evolution works? Natural Selection.

12. What two conditions are necessary for natural selection? Individuals vary hereditable

characteristics and they help individuals to survive or reproduce better.

13. What does natural selection act on? Individuals.

14. What does evolution act on? Populations.

15. What is fitness? Ability of individual to produce offspring.

16. What is an adaptation? Trait that increases fitness of an individual in a particular invironment.

17. What is speciation? Divergence process in which natural selection causes populations of one

species to diverge to form a new species.

18. What are the three domains of life? Bacteria, archaea, and eukarya.

19. What are the characteristics of a eukaryote? Membrane bound nucleus / larger

20. What are the characteristics of a prokaryote? No membrane bound nucleus / smaller

21. Which domain(s) are prokaryotes or eukaryotes? Eukaryote – eukarya. Prokaryote – bacteria

and archaea.

22. What is a phylogenetic tree? Relationships between species. Branches that share common

ancestor = species closely related. Branches w/o common ancestor = more distantly related.

23. What are the two portions of a scientific name? Genus and Species.

Chemistry

1. What is a:

a. Proton? Positively charged particles.

b. Neutron? Neutral particles.

c. Electron? Negatively charged particles.

2. What is the octet rule? atoms of low (<20) atomic number tend to combine in such a way that

they each have eight electrons in their valence shells, giving them the same electronic

configuration as a noble gas.

3. What is a covalent bond? Each atom’s unpaired valence electrons are shared by both nuclei to

fill their orbitals.

4. What is a nonpolar covalent bond? Electrons shared evenly between two atoms and

symmetrical bond.

5. What is a polar covalent bond? Electrons are asymmetrically shared.

6. What is an ionic bond? Electrons are transferred from one atom to another.

7. What is a cation? An atom that loses an electron and becomes positively charged.

8. What is an anion? An atom that gains an electron and becomes negatively charged.

9. What is a hydrogen/electron bond? Weak electrical attractions between the partially negative

oxygen of one water molecule and the partially positive hydrogen of a different water molecule.

10. What does hydrophilic mean? Atoms and molecules where ions and polar molecules stay in

solution because of their interactions with water’s partial charges.

11. What does hydrophobic mean? Uncharged and nonpolar compounds do not dissolve in water

and are said to be hydrophobic.

12. How does polar/nonpolar affect whether a compound is hydrophobic/hydrophilic? If it is

nonpolar it cant be dissolved. If it is polar (salt) it can be dissolved.

13. What is cohesion? Binding between like molecules. (results in high surface tension).

14. What is adhesion? Binding between unlike molecules.

15. Why is solid water less dense than liquid water (think hydrogen bonds)? The hydrogen bonds

form ice crystals and spread out the density.

16. What is surface tension? The tension of the surface film of a liquid caused by the attraction of

the particles in the surface layer by the bulk of the liquid, which tends to minimize surface area.

17. What is acidity a measure of (concentration of what)? Proton concentration.

18. What is alkalinity (basic) a measure of (concentration of what)? The capacity of water to

neutralize acids.

19. What is the pH of water? 7.

20. When is a pH acidic? Basic? Acidic = <7 , basic = >7

21. What is a buffer? Buffers are compounds that minimize changes in pH.

22. What is an:

a. Endothermic reaction? Must absorb heat to proceed.

b. Exothermic reaction? Release heat.

23. What type of energy (kinetic or potential) is chemical energy? Potential.

24. What two factors determine spontaneity of a reaction? The amount of potential energy and the

degree of order.

25. As a molecule increases in complexity, does entropy increase or decrease? Entropy always

increases.

26. If a molecule increases in complexity, does its potential energy increase or

decrease? Always decrease.

27. How does temperature affect chemical reactions? Higher temp->more collisions->faster

reaction.

28. How does concentration affect chemical reactions? Higher concentration->more collisions->

faster reaction.

29. What are the three general steps in the chemical evolution hypothesis? 1. Simple molecules

were present in the atmosphere of ancient earth. 2. The energy drove reactions among the simple

molecules. 3. Complex molecules formed.

Nucleic Acid Structure

1. What are monomers? Polymers? Monomer – A molecule that can be bonded to other identical

molecules to form a polymer. Polymer – a substance that has a molecular structure built up

chiefly or completely from a large number of similar units bonded together.

2. What is polymerization? A chemical process that combnes several monomers to form a

polymer or polymeric compound.

3. What type of reaction builds polymers from monomers? Condensation (dehydration) reactions.

4. What type of reaction breaks polymers down into monomers? Hydrolysis is reverse action (+

water mol.)

5. What is a nucleic acid? It’s a polymer of nucleotide monomers.

6. What is a nucleotide? A phosphate group, a sugar, and a nitrogenous base.

7. What sugar is present in:

a. RNA? Ribose.

b. DNA? Deoxyribose.

8. Which of the nitrogenous bases are:

a. Purines? Adenine, guanine

b. Pyrimidines? Cytosine, uracil, and thymine.

9. Which base is found only in RNA? DNA? RNA – uracil. DNA – thymine.

10. What type of bond holds DNA monomers together? Phosphodiester Linkage.

11. How many hydrogen bonds are found in:

a. Adenine-thymine pairs? Double H bonds

b. Cytosine-guanine pairs? Triple H bonds

12. How does RNA differ from DNA (3 main ways)? 1. RNA contains uracid instead of thymine.

2. RNA contains ribose instead of deoxyribose. 3. RNA is usually single stranded.

Carbohydrates

1. What are the simplest polysaccharides?

2. What type of bond joins monosaccharides? Glycosidic bond.

3. What is the difference between an α linkage and a β linkage? Alpha-glycosidic linkage is

below the plane of the rings and the beta glycosidic linkages (the bonds joining the simple sugar

together) are above the plane of the rings.

4. Which two carbons did we emphasize being joined by α and β linkages?

5. What is the biological importance of:

a. Starch? Stores energy. Energy released during respiration. Starch insoluable in water. Can be

stored in plants as energy source.

b. Glycogen? Storage form of glucose in animals and humans which is analogous to the starch in

plans. Glycogen is synthesized and stored mainly in the liver and the muscles.

c. Cellulose? Major component in the rigid cell walls in plants. It’s a linear polysaccharide

polymer with many glucose monosaccharide units. Humans are unable to digest cellulose because

human don’t have cellulose (enzyme which used to breakdown the cellulose).

d. Chitin? Polysaccharide found in the outer skeleton of insect, crabs, shrimps, and lobsters and in

the internal structures of other invertebrates. It is sometimes considered to be a spinoff of

cellulose, because the two are very molecularly similar. Cellulose contains a hydroxyl group, and

chitin contains acetamide.

6. What is the difference between the linkages of storage and structural

polysaccharides? Storage – stores glucose like starch and glycogen. Structural – polysacchradies

that are found to form the structure of an organism (like cellulose and chitin), whithout any

“storing ability”.

7. What are four general functions of carbohydrates? Source of energy, protein sparing action,

regulation of fat metabolism, role in gastro-intestinal function.

8. What is the major function of glycoproteins? They help to stabilize the membrane structure as

they forms hydrogen bonds with water molecules in the fluid surrounding the cell.

9. Why do carbohydrates have more free energy than CO2?

10. What process produces most sugars? Photosynthesis.

11. When starch and glycogen are hydrolyzed, what do they release? Glucose???

Proteins

1. What are the building blocks of proteins? Amino acids.

2. What type of bond joins monomers in a protein? Peptide bond.

3. What are three components of the basic structure of amino acids (in other words,

what three components do all amino acids share in common)? Amino group, side chain, carboxyl

group.

4. How many different amino acid monomers are there? 20.

5. Distinguish between an oligopeptide, a polypeptide, and a protein. Oligopeptide – fewer than

50 amino acids linked together. When amino acids are linked by peptide bonds into a chain, the

amino acids are referred to as residues and the resulting molecule is called a Polypeptide.

Polypeptides with 50 or more amino acids are Proteins.

6. What are the four basic levels of structure for proteins? Primary, Secondary, Tertiary,

Quaternary.

7. What are the two most common forms of secondary structure? Helices and B-pleated sheets.

8. What, in the cell, helps proteins fold correctly? Molecular chaperones.

9. What is an unfolded protein called? Can it function normally? Denatured Protein. No.

10. What two functions are performed by enzymes? Bring substrates together in precise

orientation so that the electrons involved in the reaction can interact. Decrease the amount of

kinetic energy reactants must have for the reaction to proceed.

11. What is the amount of free energy required to reach a transition state? Activation energy.

12. What does a catalyst do to:

a. Activation energy? Lowers the activation energy of the reaction.

b. Reaction rate? Increases the rate of reaction.

13. Where do substrates bind on an enzyme? The enzymes active site.

14. What happens in an induced fit? Where many enzymes undergo a conformational change

when the substrates are bound to the active site.

15. What are cofactors? Metal ions or small organic molecules called coenzymes.

16. What is competitive inhibition? Occurs when a molecule similar in size and shape to the

substrate competes with the substrate for access to the active site.

17. What does “enzymes are saturable” mean? The rate of a reaction is limited by the amounts of

substrate present and available enzyme.

Lipids and Membranes

1. Are lipids:

a. Hydrophobic or hydrophilic? Very hydrophobic.

b. Able to or not able to dissolve in H2O? do NOT dissolve in H2O.

c. Polar or nonpolar? nonpolar

2. What are fats? Fats are composed of three fatty acids linked in glycerol.

3. What are steroids? Steroids are a family of lipids with a distinctive four-ring structure.

4. What are phospholipids? Phospholipids consist of a glycerol linked to a phosphate group

(PO4^2-) and to either two chains of isoprene or two fatty acids.

5. What does an ester linkage do to a hydrocarbon chain? Dehydrates it.

6. What does amphipathic mean? Hydrophilic & lipophilic (loves water and fat).

7. Which portion of a phospholipid is hydrophobic? Hydrophilic? Hydrophobic tail, hydrophobic

head. = amphipathic.

8. What types of molecules move across cell membranes

a. Quickly? small or nonpolar molecules.

b. Slowly? Charged or large polar substances.

c. Hardly at all? Ions.

9. What factors influence the behavior of the membrane? Number of double bonds between the

carbons in the phospholipid’s hydrophobic tail, length of tail, number of cholesterol molecules in

the membrane, temperature.

10. How is membrane permeability affected by:

a. Saturation of hydrocarbon chains? Unsaturated are more permeable than saturated.

b. Hydrocarbon tail length? Longer tails = reduced permeability.

c. Cholesterol? lower membrane permeability.

d. Temperature? Decreased membrane fluidity causes decreased permeability.

11. What is diffusion? A form of passive transport.

12. What is osmosis? Movement of water (only occurs across a selectively permeable membrane)

13. What is a hypertonic solution? an outside solution with a higher concentration is said to be

hypertonic to the inside of a cell.

14. What is a hypotonic solution? lower concentration.

15. What is an isotonic solution? solute concentration equal outside and inside of a cell.

16. What happens to animal cells when they are in solutions that are hypertonic or

hypotonic? Hypertonic – net flow of water out of cell; cell shrinks. Hypotonic – net flow of water

into cell; cell swells or even bursts.

17. What is active transport? Cells can transport molecules or ions against an electrochemical

gradient. Process requires ATP energy (active transport).

Cells

1. What are the three basic shapes of bacteria (omit spirochete)? Spirillum, bacillus, coccus.

2. What do prokaryotes and eukaryotes share in common? Both perform basic life tasks, both can

have ribosomes and cell walls, cell membranes and cytoplasm, and have genetic material.

3. What polysaccharide makes up a bacterial cell wall? Peptidoglycan.

4. Which is the only domain of life that can be multicellular? Eukaryotes.

5. What are the four main groups of Eukarya? Protists, Kingdom fungi, Kingdom plantae,

Kingdom animalia.

6. What two advantages does compartmentalization of eukaryotic cells offer? Separation of

incompatible chemical reactions. Increasing the efficiency of chemical reactions.

7. What are the functions of the nucleus? Info storage and processing. Ribosomal RNA synthesis

(in nucleolus).

8. What is the function of mitochondria? ATP production. (source of the cells energy).

9. What is the function of chloroplasts? Convert light energy to chemical energy (photosynthesis).

10. What is the function of rough endoplasmic reticulum? Ribosomes synthesize proteins. New

protein are folded and processed in the lumen (interior).

11. What is the function of smooth endoplasmic reticulum? Synthesize fatty acids and

phospholipids, or break down poisonous lipids. Reservoir for Ca2+ ions.

12. What is the function of the Golgi apparatus? Formed by a series of stacked flat membranous

sacs called “cisternae”

13. What is endocytosis? Process by which the cell membrane can pinch off a vesicle to bring

outside material into the cell.

14. What is phagocytosis? Eating.

15. What is the endosymbiotic hypothesis?

16. What are the functions of the cytoskeleton? Shape, structure, aids cell movement, aids in

transport of materials.

17. Where are proteins folded and glycosylated? In the RER lumen. Carbohydrates are attached to

the protein.

18. What are the three types of cytoskeletal elements?

Cellular Respiration and Fermentation

1. What is a catabolic pathway? Breakdown of high energy molecules to produce ATP.

2. What is an anabolic pathway? Synthesize large molecules form smaller components.

3. What is the structure of ATP? Three phosphate groups, ribose, and adenine.

4. What is energetic coupling? ATP hydrolysis fuels endergonic reactions.

5. What is an endergonic reaction? Chemical reaction in which the standard change in free energy

is positive and energy is absorbed.

6. What is an exergonic reaction? Chemical reaction in which the change in the Gibbs free energy

is negative, indicating a spontaneous reaction.

7. What is an oxidation reaction? Loss of electrons –or- loss of H (= 1e + 1H^+).

8. What is a reduction reaction? Gain of electorns or H.

9. What is NAD (the function, not the name)? an electron carrier.

10. What are the four stages of cellular respiration? 1. Glycolysis. 2. Pyruvate processing

(intermediate stage) 3. Citric acid cycle. 4. Electron transport and chemiosmosis.

11. What happens to glucose during glycolysis? glucose is oxidized to pyruvate.

12. What happens to pyruvate during pyruvate processing? Pyruvate is oxidized to acetyl CoA.

13. What happens to acetyl CoA during the citric acid cycle? Acetyl CoA is oxidized to CO2.

14. What is substrate level phosphorylation? High energy P group added directly to ADP.

15. What is oxidative phosphorylation? ATP is synthesized as the result of an electron transport

chain (ETC).

16. Where does glycolysis occur? In the cytoplasm of both eukaryotic and prokaryotic cells.

17. What is feedback inhibition? Feedback inhibition occurs when an enzyme in a pathway is

inhibited by the product of that pathway.

18. What is an electrochemical gradient? The pumped protons across the plasma membrane into

the intermembrane space form the electrochemical gradient.

19. What is the function of electrons that have been carried by NADH and FADH2?

20. Which molecule contains the “rotor” and makes ATP from ADP and P? F0 unit.

21. Which ion makes the electrochemical gradient used to turn this rotor?

22. What molecule is the final electron acceptor? Oxygen.

23. During fermentation, which molecule accepts electrons from NADH? NAD+

24. What type of fermentation do our cells carry out? Lactic acid fermentation.

25. What organism carries out alcohol fermentation? Yeast.

Photosynthesis

1. Which organisms use photosynthesis? Plants, algae, and more.

2. What benefits are there to other species from photosynthesis? Oxygen and food.

3. What is the basic formula for photosynthesis? 6 COS + 12 H20 + light energy ->->->

C6H12O6 + 6O2 + 6H20

4. What are autotrophs? Self feeders.

5. What are heterotrophs? Different feeders.

6. What is produced in the light dependent reactions? ATP & NADPH

7. What is produced in the Calvin cycle reactions? Carbohydrates (dark reactions).

8. What are the “light particles”? photons.

9. In the cell, which organelle carries out photosynthesis? Chloroplasts.

10. What is the main photosynthetic pigment? Carotenoids.

11. What is a photosystem? Group of chlorophyll molecules that work together. 200-300

chlorophyll molecules, accessory pigments.

12. What are the elements of a photosystem? 2 major elements: antenna complex and a reaction

center, as well as proteins that capture and process excited electrons.

13. What is resonance? Red or blue photon strikes a pigment molecule in the antenna complex,

energy is absorbed and an electron excited. This energy is passed to another chlorophyll molecule

not the electron.

14. What does the electron transport chain drive? Redox reactions.

15. What is photophosphorylation? The capture of light energy by photosystem II to produce

ATP.

16. Which energy molecules are the products of photophosphorylation in the

photosystems? Oxygen.

17. What are the reactants in fixation? 3 RuBP – 3 CO2.

18. What is the product of fixation? 6 3-phosphoglycerate.

19. What is the CO2 fixing enzyme (the abbreviated form)? Rubisco.

20. Through which structure does CO2 enter leaves? Stomata.

21. What is C4 photosynthesis? 4-carbon molecule present in the first product of carbon fixation.

22. What is CAM photosynthesis? Carbon fixation pathway that evolved n some plants as an

adaption to arid conditions. Stomata in the leaves stay shut during the day.

Mitosis

1. What type of cell does mitosis produce? gametes (egg and sperm).

2. What three key events are mitosis and cytokinesis responsible for in multicellular

eukaryotes? 1. Growth. 2. Wound repair. 3. Asexual reproduction.

3. What are chromosomes? Contain a single long double helix of deoxyribonucleic acid (DNA

wrapped around proteins.

4. What are the four phases of the cell cycle (the cell cycle, not mitosis)? M, G1, S, and G2 (G1,

S, G2 = interphase).

5. When does chromosome replication happen (during which phase)? S stage of interphase.

6. How many chromosomes do humans have? 46.

7. What happens during prophase (include prometaphase)? Chromosomes condense and first

become visible in the light microcope.

8. What happens during metaphase? The formation of the mitotic spindle is completed.

9. What happens during anaphase? Centromeres split and sister chromatids are pulled by the

spindle fibers toward oppsite poles of the cell.

10. What happens during telophase? A new nuclear envelope begins to form around each set of

chromosomes.

11. What is cytokinesis? Typically occurs immediately after mitosis. During this process, the

cytoplasm divides to form two daughter cells, each with its own nucleus and complete set of

organelles.

12. How do plants carry out cytokinesis? Cell plate.

13. How do fungi and animals carry out cytokinesis? Cleavage furrow.

14. What is chromatin? The material that makes up eukaryotic chromosomes; consists of a DNA

molecule complexed with histone proteins.

15. What is a chromatid? One strand of replicated chromosome, with its associated proteins.

16. What are sister chromatids? The two strands of a replicated chromosome. When

chromosomes are replicated, they consist of two sister chromatids. The genetic material in sister

chromatids is identical. When sister chromatids separate during mitosis, they become independent

chromosomes.

17. What is G0? Non-dividing cells get permanently stuck in G1 phase; this arrested stage is

called the G0 state.

18. What is negative feedback? Occurs when a process is slowed or shut down by one of its

products.

19. What is a checkpoint? Interactions among regulatory molecules at each checkpoint allow a

cell to “decide” whether to proceed with division.

20. How can you generally define cancer in terms of cell growth? Out of control cell division.

21. What is metastasis? When cancer cells detach from the original tumor and invade other tissue.

Meiosis

1. What type of reproduction is dependent on meiosis? Sexual reproduction.

2. What is fertilization? During sexual reproduction, a sperm and an egg unite to form a new

individual.

3. What is a karyotype? Number and types of chromosomes present in an organism.

4. How many autosomes do humans have? 22 pairs of autosomes. (and 1 pair of sex

chromosomes) (46 chromosomes in every cell except their gametes).

5. What are homologous chromosomes? Chromosomes of the same type.

6. What is a haploid number? The haploid number n indicates the number of distinct types of

chromosomes present.

7. What is the haploid number of humans? 46 diploid and 23 haploid (2n).

8. What is ploidy? (n, 2n, 3n, etc.) indicates the number of each type of chromosome present. Or

the number of sets of homolog’s.

9. What are humans, in terms of ploidy (e.g., are we haploid, diploid, etc.)? diploid.

10. What is a tetrad? Homologous replicated chromosomes that are joined together.

11. Why is meiosis called a reduction division? Because meiosis reduces chromosome number by

half. In diploid organisms, the products of meiosis are haploid.

12. What is gametogenesis? In animals, daughter cells become gametes.

13. What is the basic purpose of meiosis and sexual reproduction? Meiosis produces gametes and

causes a fetus to grow.

a. What is independent assortment and how does it work towards this?

b. What is crossing over and how does it work towards this? Exchanging genetic material.

14. What is the difference between mitosis and meiosis re:

a. Number of cell divisions? Mitosis: one. Meiosis: two.

b. Number of chromosomes in daughter cells? Mitosis: same. Meiosis: half.

c. Role in organism life cycle? Mitosis: asexual reproduction in eukaryotes; cell division for

growth of multicellular organisms. Meiosis: precedes production in sexually reproducing animals.

15. What type of reproduction happens in most organisms of the tree of life? Asexual.

16. What is nondisjunction? If both homologs or both sister chromatids move to the same pole of

the parent cell, products of meiosis will be abnormal. This sort of meiotic error is referred to as

nondisjunction.

17. What happens to the incidence of Down’s syndrome as maternal age increases? Down’s

syndrome risks go up greatly.

Mendelian Genetics

1. Who worked out the rules of genetic inheritance? Gregor Mendel.

2. What is an F1 generation?

3. What is a recessive trait? The less obvious characteristic.

4. What is a dominant trait? The more obvious characteristic.

5. What is a gene? Hereditary determinants for a trait.

6. What is an allele? The two versions of a gene.

7. What is a homozygote? Two copies of the same gene.

8. What is a heterozygote? Different alleles in an individual.

9. What are mutants? One or more genes that have undergone an alteration.

10. What are sex chromosomes? Chromosome involved with determining the sex of an organism.

11. What is X-linked inheritance? The gene for white eye color in fruit flies is located on the X

chromosome and that the Y chromosome does not carry an allele of this gene. Females (XX)

would then have two copies of the gene and males…..

12. What is linkage? Gametes with new, recombinant genotypes were generated when crossing

over occurred during prophase of meiosis I in the females. Linked genes are inherited together

unless crossing over occurs.

13. What makes genes more likely to cross over?

14. What is incomplete dominance? Alleles of a gene are not always clearly dominant or

recessive. The heterozygotes have an intermediate phenotype.

15. What is codominance? A heterozygous organism that displays the phenotype of both alleles

of a single gene, neither allele is dominant or recessive to the other.

16. What is multiple allelism? Many genes have more than two alleles.

17. What is a polymorphic trait? A genetic variant that appears in at least 1% of the population.

18. What are pleiotropic genes? Genes that influence many traits.

19. What is polygenic inheritance? When a single trait is controlled by 2 or more sets of alleles.

20. What are carriers? Inherits a genetic trait or mutation but does not display it. Passes it along.

DNA Synthesis and Repair

1. What are chromosomes composed of? DNA and protein.

2. What are the two major components of the primary structure of DNA? Backbone, nitrogenous-

containing bases.

3. What is the backbone made of? Sugar and phosphate groups.

4. The two DNA strands line up in the opposite direction, meaning they are __? Antiparallel.

5. What is semiconservative replication? Parental DNA strands separate & each is used as a

template for the synthesis of a new strand. Daughter cells consist of one old & one new strand.

6. Which enzyme catalyzes DNA synthesis? DNA polymerase.

7. What is a replication fork? Y-shaped region where the DNA split into two separate strands for

copying.

8. What is a replication bubble? Forms in chromosome that is actively being replicated.

9. What is an origin of replication? Single location where replication process begins.

10. In which direction does DNA replication occur? 5’->3’

11. Which domain uses one origin of replication? Bacterial chromosomes.

12. Which domain uses multiple replication bubbles? Eukaryotes.

13. What does DNA polymerase require in order to begin working? A primer.

14. Which enzyme synthesizes a short RNA sequence that allows DNA polymerase

to begin? Primase.

15. Which strand is synthesized continuously? Leading strand, or continuous strand.

16. Which strand is synthesized in pieces? Lagging strand.

17. What are these pieces called? Okazaki fragments.

18. Which enzyme removes all the primers from the pieces? DNA polymerase I.

19. Which enzyme glues the pieces together? DNA ligase.

20. What is the name for the combined enzymes around the replication fork? Replisome.

21. How does the cell defend against shortening of chromosomes? Telomerase – enzyme, adds

nucleotides to the lagging strand, carries its own primer.

22. Which enzyme is responsible for maintaining telomeres? Telomerase.

How Genes Work

1. What is gene expression? The process of translating the information in DNA into functioning

molecules within the cell.

2. What is a genotype? Genetic constitution of an individual organism.

3. What is a phenotype? Set of observable characteristics of an individual resulting from the

interaction of its genotype with the environment.

4. What is the central dogma of biology? Summarizes the flow of information in cells. It states

that DNA codes for RNA, which codes for proteins: DNA -> RNA -> proteins.

5. Which type of RNA carries information from DNA to the site of protein synthesis? Messenger

RNA (mRNA).

6. What enzyme synthesizes RNA from DNA? RNA polymerase.

7. What is transcription? The process by which the hereditary info in DNA is copied to RNA.

8. What is translation? The process wherein the language of nucleuic acids, the order of the

nucleotide bases is converted to the language of proteins, the order of amino acids.

9. Which RNAs are not translated into proteins? tRNA and mRNA.

10. What is a codon? Group of three bases that specifies a particular amino acid.

11. What is a reading frame? Sequence of codons.

12. What is a start codon? (AUG) signifies the start of the protein-encoding sequence in mRNA

(methionine).

13. What is a stop codon? 3 stop codons (UGA, UAA, and UAG) that signal the end of the

protein-coding sequence.

14. What is a point mutation? Result from a single base change.

15. What is a chromosome-level mutation? Changes in chromosome number (polyploidy,

aneuploidy).

a. What is polyploidy? Having more than 2 sets of each chromosome (3n, 4n, etc.)

b. What is aneuploidy? The addition or deletion of a chromosome.

Transcription and Translation

1. In which direction does transcription occur? 3’->5’

2. What is the name of the strand that gets copied? Template strand.

3. What is the name of the other strand? Non-template, or coding strand.

4. What is the first phase of transcription? Initiation.

5. Where does this phase occur in eukaryotes? Nucleus. (prokaryotes – no nucleus)

6. What is the signal found within DNA for the beginning of gene transcription? Transcription

termination signal.

7. What is the elongation phase of transcription? RNA Polymerase moves along the DNA

template and synthesis RNA in the 5’->3’ direction.

8. What is the termination phase of transcription? (transcription ends) RNA polymerase

encounters a transcription termination signal in the DNA template.

9. What are introns and exons? Introns are noncoding sequences that need to be removed. Exons

are the coding regions of the mRNA.

10. How do bacterial and eukaryotic transcription/translation differ in terms of time

and space? Bacteria – coupled (time and space). Eukaryotes – separated (time and space).

11. What is the function of a tRNA? Bring amino acids to the ribosome.

12. What is the anticodon? Triplet on the loop at the opposite end. Base pairs with mRNA codon.

13. Which enzymes catalyze the addition of amino acids to tRNAs? Aminoacyl tRNA synthetases

14. Which two types of biomolecule make up ribosomes? protein and ribosomal RNA (rRNA).

15. What happens at the:

a. A site of a ribosome? Acceptor site for an aminoacyl tRNA

b. P site of a ribosome? Peptide bond forms that adds an amino acid to the growing polypeptide

chain.

c. E site of a ribosome? tRNAs no longer bound to an amino acid exit the ribosome.

16. What causes termination of translation? When the A site encounters a stop codon.

17. What type of group is added to many proteins in order to either activate or

deactivate them? Phosphate group.