Biology ECA Review

Miss Southwood’s Biology Class

● All living things are made of organic compounds

● All contain Carbon

● Bonds with:● Hydrogen● Oxygen● Phosphorus● Sulfur● Nitrogen

These 6 are the molecules of life

Organic Compounds

Macromolecules

● Carbohydrates

● Lipids

● Nucleic Acids

● Protein

● Carbohydrates (CHO)

o Monomers: monosaccharaides

glucose, galactose, fructose

o Polymers: polysaccharides (ex: disaccharides)

starch, glycogen, cellulose

● Function:

o Energy

o Structure

Macromolecules

● Lipids (CHON)

o Monomers: Fatty Acids

o Polymers: Triglycerides

● Function:

o Energy

o Structure

Macromolecules

● Nucleic Acids (CHONP)

o Monomers: nucleotide

o Polymers: DNA, RNA

● Function:

o Instructions (blueprints)

Macromolecules

● Proteins (CHONS)

o Monomers: amino acids

o Polymers: peptides

● Function:

o building and repairing cells

o communication

o regulating

o transporting

Macromolecules

● Catalyst in living things

● Specific to particular substrates

● Reusable

● Affected by temperature and pH

Enzymes

● Prokaryotes

o simple, no membrane bound organelles

o Bacteria only

o One circular chromosome

o Includes: chromosome, ribosome, plasma membrane

● Eukaryotes

o Membrane bound organelles

o Plants and animals

o True nucleus containing chromosomes

Cells

● Nucleus

o “Control Center”

o Contains chromosomes

Cells

● Mitochondria

o Power house of the cell

o Produces energy in the form of ATP

o Site of aerobic respiration

Cells

● Ribosomes

o Proteins are synthesized

o Found in both prokaryotes and eukaryotes

Cells

● Chloroplast

o Site of photosynthesis

o Plant cells ONLY

o Contains the pigment chlorophyll (green)

Cells

● Vacuole

o Storage of excess material

o Plant cells normally contain one large vacuole

Cells

● Plasma Membrane

o Surrounds the cell

o Regulates what enters/leaves the cell

o Helps maintain homeostasis

o Made of phospholipids and embedded proteins

Cells

● Cell Wall

o Found ONLY in plants

o Surrounds cell

o Provides support and structure

o Made of cellulose

Cells

•Cell Organization

Cells

● Cell Specialization

o Cells develop to perform different functions

o Regulated by genes

Cells

● Cell to Cell Communication

o Chemical signals (hormones) can be sent from one cell to another

o Receptor proteins on the membrane receive the signal

Cells

● Diffusion

o Passive transport (no energy needed) across the membrane

o Move from high concentration to low concentration

Cells

● Osmosis

o Diffusion of water

o Passive transport

Cells

● Active Transport

o Particles moving past the concentration gradient

o Requires ENERGY (ATP)

o Low concentration to high concentration

Cells

● ATP (adenosine triphosphate)o Energy storing moleculeo Can be used for quick

energy by the cello Energy is stored in the

phosphate bonds

Cells

● Water and carbon dioxide are used to produce glucose and oxygen● 6CO2 + 6H2O (+ light energy) → C6H12O6 + 6O2● Occurs in chloroplast

Photosynthesis

● Used to release energy (ATP) for cellular use

● glucose + oxygen water + carbon dioxide (+ energy)

● C6H12O6 + 6O2 → 6H2O + 6CO2 + ATP

● Occurs in mitochondria

Aerobic Respiration

● Does not require oxygen● Used to release energy

o Not as efficient as aerobic respiration (less ATP)● Products include CO2 and lactic acid or alcohol● Two types:

Alcohol Fermentation Lactic Acid Fermentation

Anaerobic Respiration

● Carries genetic information● Made of a chain of nucleotides● Nucleotides contain:

o Sugar● DNA: Deoxyribose● RNA: Ribose

o Phosphateo Nitrogen base

DNA / RNA

● DNAo Double strand (double helix)o Four base pairs: ATGCo Found in nucleus

● RNAo Single strando Four base pairs: AUGC

DNA / RNA

● Base Pairing Ruleo DNA

● A ←→ T● G ←→ C

o RNA● A ←→ U● G ←→ C

DNA / RNA

● Replicationo Making an identical

strand of DNAo DNA helicase “unzips”

and unwindso DNA polymerase adds

complementary bases

DNA / RNA

● Central Dogmao DNA → RNA → Protein → Trait

DNA / RNA

● Transcriptiono DNA mRNAo Occurs in nucleuso Complementary mRNA strand is produced from a DNA segment

DNA / RNA

● Translationo Connects amino acids

to create proteinso Occurs in the

cytoplasm within the ribosomes

DNA / RNA

● Codonso Sequence of three mRNA baseso Code for an amino acido 64 amino acids

● 4x4x4=64

DNA / RNA

● Mutationso Change in the DNA codeo May cause a different protein to be producedo Types:

Frame shift (bases added or deleted) Substitution (Bases is changed)

● Silent: does not change the amino acid

DNA / RNA

• Cell division

• Produces two identical daughter cells (diploid)

• Occurs in body cells to grow and repair

Mitosis

• Error in cell growth that causes uncontrollable cell growth

• Can be caused by genetics and environment

Cancer

• Cell division

• Produces 4 different haploid daughter cells

• Occurs in sex cells to form gametes

Meiosis

• Crossing over

• Homologous chromosomes exchange parts of their DNA

• Creates variation in gametes

Meiosis

• Homologous chromosomes fail to separate during meiosis

• Can lead to disorders such as: Down Syndrome, Turners and Klinefelters Syndrome

Nondisjunction

Asexual Reproduction

• One parent

• Identical offspring

• Variation only through mutations

• Examples: budding, fragmentation, fission

Asexual VS Sexual Reproduction

Sexual Reproduction

• Two parents

• Offspring different from parents

• More variation

• Fertilization (fusion of gametes

• Traits are specific characteristics that are inherited from their parents

• Genes are the factors that determine traits

• Different forms of a gene are called alleles

Inheritance

• Dominant alleles will be expressed when present

• Recessive allele will only be expressed if paired with another recessive allele

Dominant and Recessive

• Actual alleles an individual has for a trait

• Homozygous: Same alleles

• Homozygous Dominant: two dominant alleles (BB)

• Homozygous Recessive: two recessive alleles (bb)

• Heterozygous: Two different alleles (Bb)

Genotype

• The actual characteristic displayed by the individual

• Example: eye color, hair color, dimples, etc.

Phenotype

• A heterozygous shows a “blending” of a dominant and recessive

• Dominant is not fully expressed

Incomplete Dominance

• When a gene has more than one dominant allele

• Both dominant alleles are expressed

Codominance

• Traits that are influenced by more than one gene

• Example: Height, skin color

Polygenic Traits

• When there are more than two alleles for a trait

• Example:

Multiple Alleles

• Sex Chromosomes

• Male: XY

• Female: XX

• Sex linked traits are carried on the X chromosome

• Examples: Hemophilia and colorblindness

Sex-linked Traits

• Punnett Square

• Used to determine the probable outcome of the offspring

• Test Cross

• Used to determine the phenotype of an unknown dominant individual

• Uses a homozygous individual as a “test”

Test Cross

• Similar to a family tree

• Shows the pattern of inheritance of a specific trait through a family

Pedigrees

• Picture of someone’s chromosomes

• Can detect chromosomal disorders

Karyotypes

• Sequencing of human DNA

• Used to help develop gene therapies

Human Genome Project

• Theory of Evolution

• Fit organisms survive and reproduce to pass on traits

• Requirements:

• Competition

• Variation

Natural Selection

• Traits that increase survival

• Examples: Beaks that make eating insects easier, bright flowers that attract pollinators

Adaptation

• Fossil Record

• Biochemical Similarities

• Shared anatomical structures

Evidence of Evolution

• Evolution of a new species

• Must be isolations between species

Speciation

• Two organisms evolve in response to each other

• Example:

• Flowering plants and their pollinators

Coevolution

• Convergent Evolution

• When two species evolve to have similar traits

• Bats and butterflies

• Divergent Evolution

• When two similar organisms evolve separately from each other

• Finches (beaks)

Convergent and Divergent

• Two word naming system

• Scientific name

• Genus species written in italicize

• Genus = first letter Capitalized

• Species = all lowercase

Binomial Nomenclature

• Example: Dog

• Canis familiaris

• Used to identify organisms

• Paired set of questions with two choices

Dichotomous Key

• Domain• Kingdom• Phylum• Class• Order• Family• Genus• Specie

Levels of Classification

Phylogenetic Tree