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Introduction to Introduction to BiologyBiology

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Complexity of LifeComplexity of Life

• Biology is the study of Biology is the study of lifelife (bacteria, (bacteria, protists, fungi, plants, animals)protists, fungi, plants, animals)

• Subject is very complexSubject is very complex

• Scientists strive to understand living Scientists strive to understand living processes in order to processes in order to improve and improve and prolong lifeprolong life. .

• The more we learn about life, the The more we learn about life, the more we appreciate its wonder!more we appreciate its wonder!

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All Living Things Share All Living Things Share Common Common CharacteristicsCharacteristics1.1. All organisms are made of All organisms are made of cellscells

- - A cell is the smallest working A cell is the smallest working unitunit

of life.of life.

UnicellularUnicellular Organisms MulticellulaMulticellular Organisms

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2. Reproduction2. Reproduction•Living thingsLiving things reproducereproduce. . If this did not occur, If this did not occur, species would species would die out. Two types:

•sexual- two cells from different parents unite to produce the first cell of the new organism

•asexual – in which the new organism has a single parent.

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3. Growth & Development3. Growth & Development•All living things grow during at least part of their livesAll living things grow during at least part of their lives

•Growth - Growth - occurs as the result of cell division and cell cell division and cell enlargement.enlargement.

•DevelopmentDevelopment – – process through which an adult process through which an adult organism arises through repeated cell divisions and organism arises through repeated cell divisions and differentiation of those cells to form the various types differentiation of those cells to form the various types of body cells. of body cells.

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Growth & Development – Growth & Development – What’s the Difference?What’s the Difference?

•OrganismsOrganisms growgrow by by producing MORE producing MORE CELLS & by cell CELLS & by cell ENLARGEMENTENLARGEMENT

•OrganismsOrganisms developdevelop as they mature into as they mature into an adult organisman adult organism

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4. Energy Utilization4. Energy Utilization

• organisms take in energy and transform it to do many kinds of work.

• Ultimate source is the sun. • Producers/Autotrophs convert sun’s

energy into useable energy by a process called photosynthesis.photosynthesis.

•Most other organisms rely on the energy stored during photosynthesis – these organisms are known as heterotrophs. •Examples - herbivoresherbivores, , carnivorescarnivores, , omnivoresomnivores, and , and decomposersdecomposers

Energy Utilization – cont.

•Metabolism - the combination of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes.•Ex. - Cellular respiration, photosynthesis, digestion, protein synthesis

Energy Utilization – cont.

6O2 + C6H12O6 6CO2 + 6H2O

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5. Organisms Respond to 5. Organisms Respond to StimuliStimuli• Living things respond to environmental cues Living things respond to environmental cues

or or stimulistimuli..

• Some stimuli are Some stimuli are externalexternal (light and (light and temperature), other stimuli are temperature), other stimuli are internal internal (blood glucose level). (blood glucose level).

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6. Homeostasis6. Homeostasis

•“internal harmony”; maintaining internal equilibrium.•Involves internal feedback mechanisms that work like a thermostat•Ex: pH, body temperature, water Ex: pH, body temperature, water balance, etc.balance, etc.

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7. Evolutionary Adaptation 7. Evolutionary Adaptation

•As a group, any species can evolve, or change over time. •Life evolves in response to interactions between organisms and ttheir environmentheir environment. •Ex. Plants in the Namibian desert have adaptedadapted to the extreme hot and dry conditions.

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8. Universal Genetic Code8. Universal Genetic Code

•The instructions for inheritance are carried by a molecule called deoxyribonucleic acid, or DNA. •This genetic code, with few minor variations, determines the inherited traits of every organism on Earth.

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B. Hierarchies of OrganizationB. Hierarchies of Organization

•As the hierarchy is explored, special qualities, called emergent properties result from the structure at each level.•There are 4 major hierarchies:

•Biological Structure•Cellular Organization•Kingdoms•Biological Systems

1. Biological Structure – atoms molecules organelles cells. The cell is the _basic unit_ of structure and function of all living things. In multicellular organisms, the order flows from cell _tissue organ organ systemorganism.

B. Hierarchies of Organization - B. Hierarchies of Organization - contcont

2. Cellular Organization – Cells can be organized as prokaryotic (without a nucleus and membrane bound organelles), or eukaryotic(with a nucleus and membrane bound organelles.

B. Hierarchies of Organization - B. Hierarchies of Organization - contcont

3. Kingdoms – Living things are organized by their structural complexity and placed into one of six kingdoms. Archaebacteria Eubacteria Protista Fungi PlantaeAnimalia

B. Hierarchies of Organization - B. Hierarchies of Organization - contcont

B. Hierarchies of Organization - B. Hierarchies of Organization - contcont4. Biological Systems – There are levels of organization beyond the individual organism. For example… organisms populations communitiesecosystems biomes biosphere.

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BASIC CHEMISTRYBASIC CHEMISTRY

Why study Chemistry in Why study Chemistry in Biology?Biology?

• Biology - study of Biology - study of LIFE!LIFE!

• Chemistry - Chemistry - part of chemistry part of chemistry deals with chemical compounds…. deals with chemical compounds…. And chemical compounds are And chemical compounds are important to living things.important to living things.

• Ex:Ex: glucose- Cglucose- C66HH1212OO66

water - Hwater - H22O O salt - NaCl salt - NaCl

Composition of MatterComposition of Matter

• MatterMatter - - Everything in Everything in universe is composed universe is composed of matterof matter– Matter is anything Matter is anything

that occupies space that occupies space or has massor has mass

•Mass Mass – – quantity of quantity of matter an object matter an object hashas

ElementsElements

• Pure Pure substances substances that cannot be that cannot be broken down broken down chemically into chemically into simpler kinds simpler kinds of matter of matter

• More than 100 More than 100 elements elements ((9292 naturally naturally occurring)occurring)

• 99% of the mass of an organism is 99% of the mass of an organism is composed of 6 elementscomposed of 6 elements (SPONCH)(SPONCH)

sulfur (S), sulfur (S),

phosphorus (P), phosphorus (P),

oxygen (O), oxygen (O),

nitrogen (N), nitrogen (N),

carbon (C), carbon (C),

hydrogen (H) hydrogen (H)

• Remaining 1% is composed of trace Remaining 1% is composed of trace elements required by an organism in elements required by an organism in minute amounts. minute amounts.

Iron (Fe)Iron (Fe)

Iodine (I)Iodine (I)

Copper (Cu)Copper (Cu)

Zinc (Zn)Zinc (Zn)

CompoundsCompounds

• Most Most elements do elements do not exist by not exist by themselvesthemselves

• Readily Readily combine with combine with other in a other in a fifielementselements xed ratioxed ratio

• AA compound compound is a is a substance made up of substance made up of atoms of two or more atoms of two or more elementselements– The proportion of The proportion of

atoms are always atoms are always fixedfixed

• Chemical formula Chemical formula shows the kind and shows the kind and proportion of atoms of proportion of atoms of each element that each element that occurs in a particular occurs in a particular compoundcompound

• Atoms in compounds are held together by Atoms in compounds are held together by chemical bonds. The tendency of elements chemical bonds. The tendency of elements to combine and form compounds depends to combine and form compounds depends on the number and arrangement of on the number and arrangement of electrons in their outermost energy level - electrons in their outermost energy level - called called valence electronsvalence electrons

Chemical Bonds

•The chemical bonds The chemical bonds that are important to that are important to Biology are Biology are covalent, covalent, ionic, and hydrogen ionic, and hydrogen bonds.bonds.

Covalent BondsCovalent Bonds• Formed by the Formed by the sharingsharing

one or more pairs of one or more pairs of valence electrons of valence electrons of two atoms.two atoms.

• Strongest Strongest type of bondtype of bond

• Impt to living thingsImpt to living things

• Found inFound in Biomolecules Biomolecules

• Resulting substance is Resulting substance is stablestable, , and is referred and is referred to as ato as a moleculemolecule..

Ionic BondsIonic Bonds

• Formed between two atoms when one Formed between two atoms when one atom atom losesloses an electron, and the other an electron, and the other atom atom gainsgains an electron. an electron.

• This giving & receiving results in This giving & receiving results in charged particles known as charged particles known as ions - ions - they they have an uneven # of have an uneven # of protonsprotons andand electrons.electrons.

Hydrogen BondsHydrogen Bonds

• Occurs when H+ (which is already Occurs when H+ (which is already bonded to an electronegative atom) bonded to an electronegative atom) is ATTRACTED to another is ATTRACTED to another electronegativeelectronegative atomatom. .

• VeryVery weakweak bondbond

• Occurs between Occurs between moleculesmolecules, , not not elements.elements.

• Important inImportant in DNA, waterDNA, water..

• Weak attraction - does NOT involve Weak attraction - does NOT involve sharing or transferring of electrons.sharing or transferring of electrons.

DNA

Water