Exam 1

Question 1

What is cell theory?

Answer 1

• all living organisms are made up of cells
• cells are the most basic organizational units
• all cells come from preexisting cells

Question 2

what are some advantages of phase contrast over bright field?

Answer 2

• increased contrast
• higher magnifications

Question 3

how do you improve the resolution of a light microscope?

Answer 3

adjust the course and fine focus

Question 4

characteristics of carbon

Answer 4

• valence of 4
• most likely to bond with oxygen, hydrogen, nitrogen, and sulfur

Question 5

how are covalent bonds formed?

Answer 5

by the sharing of a pair of electrons between two atoms

Question 6

what is electronegativity

Answer 6

an atom’s tendency to attract electron to itself in a chemical bond

Question 7

what makes water a versatile solvent?

Answer 7

its charges are really efficient at breaking other molecules up

Question 8

non-polar bonds

Answer 8

share electrons equally

Question 9

polar bonds

Answer 9

share electrons unequally

Question 10

phosphodiester bonds

Answer 10

covalent bonds that link the 5’ phosphate group of one nucleotide to the 3’ hydroxyl group of another

Question 11

glycosidic bond

Answer 11

covalent bonds that connect a carbohydrate molecule to another molecule

Question 12

Dehydration reaction

Answer 12

a chemical reaction that involves the removal of a water molecule, allowing two molecules to bond together

Question 13

Hydrolysis reaction

Answer 13

a chemical reaction that involves the addition of water to break a bond in a polymer, splitting it into smaller units

Question 14

peptide bonds

Answer 14

covalent bonds formed between the carboxyl group of one amino acid and the amino group of another

Question 15

Virus

Answer 15

a microscopic infectious agent that can replicate only inside the living cells of an organism

Question 16

Viroid

Answer 16

a small, circular piece of RNA that is infectious and can cause disease in plants. Lacks a protein coat

Question 17

Allosteric inhibition

Answer 17

a mechanism where a molecule binds to a site other than the active site on an enzyme. causes a change in shape and reduces the enzyme’s activity

Question 18

feedback inhibition

Answer 18

a process in which the end product of a metabolic pathway inhibits an earlier step in the pathway

Question 19

Michaelis Constant (Km)

Answer 19

a measure of the substrate concentration at which an enzyme-catalyzed reaction proceeds at half its maximum velocity

Question 20

Vmax

Answer 20

the maximum rate of an enzyme-catalyzed reaction when the enzyme is saturated with substrate

Question 21

Endosymbiont theory

Answer 21

the origin of mitochondria and chloroplasts evolved from free-living prokaryotic cells that were engulfed by ancestral eukaryotic cells

Question 22

how does an ionic bond form?

Answer 22

when one atoms donates an electron to another atom

Question 23

features of hydrocarbons

Answer 23

organic compounds
composed of only C and H
can be linear or branched

Question 24

describe amino acid structure

Answer 24

central carbon atom bonded to an amino group, a carboxyl group, a H atom, and an R-group (side chain)

Question 25

Types of R-groups

Answer 25

* can be nonpolar (hydrophobic), * polar (hydrophilic), * acidic (negatively charged, or * basic (positively charged)

Question 26

directionality in cell biology

Answer 26

refers to the orientation of biological molecules

Question 27

Primary protein structure

Answer 27

linear sequence

Question 28

secondary protein structure

Answer 28

local folding patterns

Question 29

tertiary structure

Answer 29

overall 3D shape of a protein

Question 30

what forms links in polysaccharides

Answer 30

glycosidic bonds

Question 31

what kind of bonding for sugars

Answer 31

glycosidic

Question 32

functions of sugars

Answer 32

serve as immediate energy sources

Question 33

Hydroxyl group

Answer 33

polar, forms H bonds, increases solubility

Question 34

carbonyl group

Answer 34

can be an aldehyde or ketone

Question 35

carboxyl group

Answer 35

acts as an acid (donates H+) polar, and hydrophilic

Question 36

amino group

Answer 36

acts as a base (accepts H+), polar, and hydrophilic

Question 37

sulfhydryl group

Answer 37

can form disulfide bonds, slightly polar

Question 38

membrane proteins

Answer 38

proteins embedded in or associated with the lipid bilayer

Question 39

principle of synthesis by polymerization

Answer 39

Monomers make covalent bonds, form polymers via dehydration reactions

Question 40

self-assembly

Answer 40

the process by which molecules automatically organize into structures arrangements without external guidance

Question 41

covalent bonds

Answer 41

strongest, include disulfide bridges

Question 42

ionic bonds

Answer 42

attractions between positively and negatively charged side chains

Question 43

hydrophobic interactions

Answer 43

nonpolar R-groups aggregate to avoid water, driving protein folding

Question 44

van der waals forces

Answer 44

weak attractions between closely positioned nonpolar molecules, stabilizing protein structure

Question 45

DNA

Answer 45

double helix, contains thymine and has a stable structure

Question 46

RNA

Answer 46

single stranded, ribonucleic acid, contains uracil, less stable

Question 47

Nucleotide structure

Answer 47

composed of a phospate group, a sugar, and a nitrogenous base

Question 48

saturated fatty acids

Answer 48

no double bonds, solid at room temp

Question 49

unsaturated fatty acids

Answer 49

one or more double bonds, liquid at room temp

Question 50

trans fats

Answer 50

unsaturated with trans configuration

Question 51

phospholipids

Answer 51

composed of 2 fatty acids and phosphate group

Question 52

steroids

Answer 52

lipids characterized by a carbon skeleton of four fused rings

Question 53

golgi apparatus

Answer 53

stack of membrane-bound vesicles that modify, sort, and package proteins and lipids for secretion or delivery to organelles

Question 54

lysosomes

Answer 54

membrane-bond organelles containing digestive enzymes. break down waste and cellular debris

Question 55

first law of thermodynamics

Answer 55

energy cannot be created or destroyed

Question 56

second law of thermodynamics

Answer 56

in any energy transfer, entropy increases

Question 57

endergonic

Answer 57

require energy input. non-spontaneous

Question 58

exergonic

Answer 58

release energy, spontaneous

Question 59

amylase

Answer 59

catalyzes the breakdown of starch into sugars

Question 60

DNA polymerase

Answer 60

catalyzes the synthesis of DNA during replication

Question 61

catalase

Answer 61

breaks down hydrogen peroxide into water and oxygen

Question 62

activation energy

Answer 62

min energy required for a chemical reaction to occur

Question 63

transition state

Answer 63

an unstable state that occurs during the transformation of reactants to products, characterized by a peak in energy

Question 64

hydrolases

Answer 64

catalyze hydrolysis reactions

Question 65

oxidoreductases

Answer 65

catalyze redox reactions

Question 66

transferases

Answer 66

transfer functional groups between molecules

Question 67

lyases

Answer 67

catalyze the addition or removal of groups to form double bonds

Question 68

isomerases

Answer 68

catalyze isomerization reactions

Question 69

ligases

Answer 69

catalyze the joining of two molecules with the use of ATP

Question 70

cofactors

Answer 70

assist enzyme activity by stabilizing structures or participating in the reaction

Question 71

coenzymes

Answer 71

act as carries for chemical groups or electrons during enzymes-catalyzes reactions

Question 72

Michaelis plot

Answer 72

[substrate] increased = rxn rate increased

Question 73

lineweaver-burke plot

Answer 73

double reciprocal plot