BI 221z: Exam 1 OCTOBER 26th

what is a Hypothesis

assumption or idea that can be tested

what is the Theory of Natural Selection

process through which populations of living organisms adapt and change

What is biology?

The scientific study of life

What is life?

Things that require moving, growing, reproducing, and other cellular activities that require energy

What is the scientific method?

step by step process used to explore observations, test ideas, and answer questions about the natural world while reducing human bias

What are the steps of the scientific method?

1) Observations/Initial info

2) Question

3) Hypothesis

4) Prediction

5) Test

6) Analysis and conclusion

7) communication

What is evidence, what does it include?

What you know, direct observations

• includes quantitative and qualitative data

What are examples of quantitative data?

numbers, height, mass, age

What are examples of qualitative data?

color, texture, taste

what is an inference?

a “guess” based on evidence and outside information

What is a controlled experiment?

an experiment that demonstrates the effect of one variable by testing control groups and experimental groups differing in only that on variable

what is an independent (explanatory) variable?

variable being manipulated

what is a dependent variable?

variable that is predicted to be impacted by independent variable

What are the levels of biological organizations?

1) The biosphere

2) Ecosystems

3) Communities

4) Populations

5) Organisms

6) Organs

7) Tissues

8) Cells

9) Organelles

10) Molecules

What is the process of gene expression?

1) DNA

2) Transcription

3) Translation

4) Protein folding

What is an example of an independent variable in the mouse experiment?

the color of the mouse model

What is an example of an dependent variable in the mouse experiment?

the amount of predation in response to the color of the mouse model

What are the unifying themes in biology>

1) Organization

2) Information

3) Energy and Matter

4) Interactions

5) evolution

what is a eukaryotic cell? What are they bigger than?

a cell that contains a membrane-enclosed organelle and a DNA containing nucleus

• bigger than prokaryotic cells

what is a prokaryotic cell?

a cell that lacks a nucleus and other membrane enclose organelles

What is DNA?

genetic material within a cell

Can hypotheses be proven?

No

What is a scientific theory, can it change?

an untested speculation that is supported by a greater body of evidence compared to a hypothesis

• theories can be changed by scientists

what is the cyclic nature of the scientific method?

scientific inquiry operates as a contionous loop rather than a straight line, there is always room for new questions

what is scientific literature?

published scholarly research and reports written by and for experts in science

what is science?

an approach to understanding the natural world

what is evolution?

process where species gain differences from their ancestors as they adapt to different environments overtime

what is natural selection?

process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits

What are tbe seven pillars of life? (by koshland)

PICERAS

1) Program

2) Improvisation

3) Compartmentalization

4) Energy

5) regeneration

6) Adaptability

7) Seclusion

how do electrons possess energy?

by their distance from the nucleus

What kind of energy do far away electrons possess?

greater/higher potential energy, harder to move up (think of walking up the stairs)

how do electrons move up a shell?

It absorbs energy

how do electrons move down a shell?

by losing its energy and released as visible light or ultraviolet radiation

What are the major elements in the human body?

CHON

what is energy?

The capacity to cause change, or do work

How many electrons can be in the second and third shell?

8 electrons

What are valence electrons?

an electron in the outermost shell

What is a polar covalent bond?

bond between atoms with different electronegativity, where shared electrons are pulled closer to the more electronegative atom

What is a covalent bond?

strongest chemical bond in which two atoms share one or more pairs of valence electrons

What is a hydrogen bond?

weakest chemical bond formed when slightest positive hydorgen atom in a polar covalent bond is attracted to a slightly negative atom of another polar covalent bond

What is a nonpolar covalent bond?

a covalent bond where electrons are shared equally in two atoms of similar electronegativitiy

what is a molecule?

two or more atoms held together by a covalent bond

what is an element

substance that cannot be broken down to any other substances

what is an atom?

smallest unit of matter that retains the properties of an element

what is a single bond?

a covalent bond that shares a pair of valence electrons by two atoms

what is a double bond

a covalent bond that shares 2 pair of valence electrons by two atoms

What is electronegativity?

the attraction of a given atom for the electrons of a covalent bond

What happens to a more electronegative atom?

the more strongly it pulls shared electrons torwards itself

What does pH represent?

the products of H+ and OH- concentrations at constant 10^-14

What is an acidic pH?

anything less than 7 due to the additional concentration of hydrogen ions (H+)

What is a basic pH?

anything more than 7 due to the additional concentration of hydroxide ions (OH-)

what is an ionic bond?

a chemical bond due to the attraction between oppositely charged ions

what is van der waals interaction?

weak attractions between molecules or parts of molecules that result from transient local charges

what is a solute?

substance dissolved in a solution

what is a solvent?

What dissolves the solute (ex: water)

what is the function of a carbohydrate?

provides body with energy for cellular activity

what is a carbohydrates composed of?

A carbonyl group and multiple hydroxyl groups

what is the function of lipids?

energy storage

Are lipids a macromolecule?

No

What is a lipids basic structure?

A glycerol molecule joined with two or three fatty acids

what are the main functions of proteins

speed up chemical reactions, play a role in defense, storage, transport, cellular communciation, movement, or structural support

what are the two types of nucleic acids?

DNA and RNA

what is the function of nucleic acids

helps living organisms reproduce their complex components from one generation to the next.

What is a nucleic acid composed of?

a nitrogenous base, a five-carbon sugar, and one to three phosphate groups

what is the difference between DNA and RNA

RNA is a single stranded molecule

which monosaccharides are sucrose made of? What links them?

glucose and fructose

• glycosidic linkages

what kind of storage polysaccharide do plants store?

Starch, a polymer of glucose monomers

what kind of storage polysaccharide do Animals store? and where?

glycogen, in liver and muscle cells

what is the nucleotide structure of a pyrimidine like?

one six-membered ring of carbon and nitrogen atoms

what is the nucleotide structure of a purine like?

larger than pyrimidine, with a six-membered ring of carbon and nitrogen atoms

what are the members of the pyrimidine family?

Cytosine (C), Thymine (T), and Uracil (U)

what are the members of the Purine family?

Guanfacine (G), and Adenine (A)

what sugar is attached to DNA, what does it lack?

Deoxyribones, it lacks oxygen

What sugar is attached to RNA?

ribose

what is the structure of a polynucleotide?

a nitrogenous base, a sugar, and a phosphate group

what kind of linkage/bond do nucleotides have and what kind of reaction is it?

phosphodiester linkage, covalent bond, condensation reaction

what is the polarity/chemical directionality of a nucleic acid?

it runs in a from a 5’ end (with a free phosphate group) to a 3’ end (with a free hydroxyl group)

what is the polarity/chemical directionality of DNA?

it has two complementary strands running in opposite directions (antiparallel) from a 5’ end (with a free phosphate group) to a 3’ end (with a free hydroxyl group)

what holds the two strands in DNA together? Where?

Hydrogen bonds, between pairs of nitrogenous bases

What does a dissacharride consist of? What linkage/bond does it have and by what reaction?

Consist of monossacharide, glycosidic linkages, covalent bond, dehydration synthesis

what are the structural differences between starch and cellulose?

starch is largely helical, while a cellulose molecule straight

How are polypeptide chains formed? What reaction?

carboxyl group of an amino acid must be adjacent to the amino group of another, resulting in a covalent bond called a peptide bond via dehydration synthesis

what are primary proteins made out of?

a sequence of amino acids

what are secondary proteins made out of? What bonds hold them together?

alpha helix and beta pleated sheats, held together by hydrogen bonds

what is a tertiary protein structures like? What kinds of bonds are present?

it’s an overall shape of a polypeptide from interactions between the side chains (R groups) of various amino acids. All sorts of bonds!

what are Quaternary protein structures composed of? What is an example?

two or more polypeptides, collagen

Are fats polymers or large macromolecules

large macromolecules

Why are fats hydrophobic?

because it is made up of nonpolar C-H bonds in the hydrocarbon chains of fatty acids

what kind of linkage do fats have and what reaction occurs?

ester linkage, dehydration synthesis

What is a saturated fatty acid composed of? Examples?

composed of a zig-zag hydrocarbon chain, where at room temp fats are packed closely to each other

• ex: butter

What is a unsaturated fatty acid composed of? Examples?

of one or more double bonds, with one fewer hydrogen atom on each double-bonded carbon. Creates a kink!

• ex: olive oil

What is a steroid, what is it composed of?

lipids characterized by a carbon skeleton composed of four fused rings.

What is a phospholipid composed of?

two fatty acids attached to glycerol

How does the structure of phospholipids result in a fluid membrane?

the hydrophillic head and hydrophobic tail forms a boundary between the cell and its external environment and establishes separate compartments within eukaryotic cells

What is the steps of gene expression?

DNA → RNA synthesis → protein synthesis

What is polymer synthesis and how is it broken down? What are the names of these reactions>

a chemical reaction where monomers covalently bond to form polymer structures via dehydration synthesis. It is broken down by hydrolysis (due to the addition of water).

Why are polymers hydrolyzed?

When food in our body needs to be broken down it is broken down via hydrolysis which helps provide energy for cellular activity.

What are two ways organisms use polysaccharides

storage material for cells (starch & glycogen), and building material for structures

Why is glucose useful for cellular processes?

it cna be stored and used a nutrients for cells as well as energy

What are enzymes? Why are they important?

proteins accelerate chemical reactions by acting as catalyst