Lecture 4: Molecules, energy, and Biosynthesis

Question 1

____ - diverse group of water-insoluble
biological molecules;

Answer 1

Lipids

Question 2

energy stores

Answer 2

fats

Question 3

Major components of membrane

Answer 3

phospholipids and sterols

Question 4

Addition of 3h2o to triglyceride results to what products??

Answer 4

Glycerol and fatty acids

Question 5

_ polyhydroxy aldehydes and ketones with the general formula of (CH2O)n

Answer 5

Carbohydrates

Question 6

examples of monosaccharide sugars

Answer 6

1. Glucose
2. Galactose
3. fructose
4. ribose
5. 2-deoxyribose

Question 7

examples of disaccharide sugars

Answer 7

1. sucrose
2. lactose

Question 8

____ – most complex and most abundant
organic molecules containing at least one
carboxyl group and one amino group.

Answer 8

Proteins

Question 9

____ carries coded information,
arranged into genes

Answer 9

DNA

Question 10

DNA carries coded information,
arranged into ____

Answer 10

genes

Question 11

_____ instrumental in translating the coded message of DNA into sequences of amino acids during synthesis of protein molecules

Answer 11

RNA

Question 12

difference between DNA and RNA ?

Answer 12

2’ H in DNA , 2’ OH in RNA

Question 13

The process of increasing the rate of
reaction with the use of a catalyst.

Answer 13

Catalysis

Question 14

____ - any substance that increases rate
of reaction upon addition to a certain
reaction .

Answer 14

Catalyst

Question 15

____ catalyst of biochemical reactions (biological catalysts)

Answer 15

enzymes

Question 16

___ neither used up in the reaction nor do they appear as reaction products

• are proteins of very specific amino acid
  composition and sequence

Answer 16

Enzymes

Question 17

Substrate + enzyme (enzyme substrate complex) = ______

Answer 17

Product + enzyme

Question 18

enzymes can be denatured and precipitated with ____, ____, ____

Answer 18

salts, solvents, and other reagents

Question 19

____ catalyze all the synthetic and metabolic
reactions of the cell
- allows for a faster speed of reaction
- increases the reaction rates by means of
lowering the energy of activation

Answer 19

Enzymes

Question 20

enzymes increases the reaction rates by means of _______

Answer 20

lowering the energy of activation

Question 21

• the kinetic energy required to bring the
  reactants into position to interact.
• measured as the number of calories required to bring all the molecules in a mole of reactant at a given temperature to a reactive (or activated) state.

Answer 21

Activation energy/free energy of activation

Question 22

How do enzymes hasten the reaction?

Answer 22

enzymes lowers the activation energy

Question 23

___ each enzyme is specific for a certain substrate (reactant molecule)

Answer 23

enzyme specificity

Question 24

___ highly specific nature of most enzymes arises from the close and complementary fit between enzymes and substrate in a special portion of the enzyme surface.

• where the substrate can fit like a lock-and-key mechanism

Answer 24

Active site

Question 25

- enzyme molecule is made up of one or more peptide chains folded to form a more or less globular protein of a specific conformation

Answer 25

Enzyme Specificity

Question 26

two types of enzyme model

Answer 26

1. lock-and-key model 2. Induced-fit model

Question 27

____ – catalytic potency of an enzyme

Answer 27

enzyme activity

Question 28

_____ – number of reactions catalyzed per second by the enzyme

Answer 28

Turnover number

Question 29

enzymatic reaction

Answer 29

- substrate interacts with the active site of the enzyme - forming an enzyme-substrate complex (ES) - product separates from the enzyme - free enzyme can form an ES complex with a new substrate molecule

Question 30

Factors affecting enzyme activity

Answer 30

1. Temperature and reaction rates 2. pH

Question 31

The higher the temp., the higher the average molecular velocity, the higher the number of molecular collision per unit, the higher the probability of successful interaction of the reactant molecules.

Question 32

as their velocities ____, the molecules possess higher kinetic energies and thus are more likely to react upon collision.

Answer 32

increase

Question 33

Drop in __ exposes more positive sites on an enzyme for interaction with negative groups on a substrate molecule

Answer 33

pH

Question 34

rise in ____facilitates the binding of positive groups on a substrate to negative sites on the enzymes.

Answer 34

pH

Question 35

enzyme require ___ for activity

Answer 35

cofactor

Question 36

____ - small organic molecules that act as cofactors

Answer 36

coenzyme

Question 37

____ – enzyme minus its cofactor; cannot function without its cofactor/coenzyme

Answer 37

Apoenzyme

Question 38

Cofactor (coenzyme, prosthetic group or metal ion) + apoenzyme =

Answer 38

holoenzyme

Question 39

Six major classes of enzymes

Answer 39

1. Oxidoreductase 2. Transferase 3. Hydrolase 4. Lyase 5.Isomerase 6.Ligase

Question 40

Type of reaction of oxidoreductase

Answer 40

Oxidation-reduction

Question 41

Type of reaction for tranferase

Answer 41

group transfer

Question 42

Type of reaction for hydrolayses

Answer 42

Hydrolysis reactions (transfer of functional groups to water)

Question 43

Type of reaction for lyases

Answer 43

Addition or removal of groups to form double bonds

Question 44

Type of reaction for isomerases

Answer 44

isomerization

Question 45

Type of reaction for ligase

Answer 45

Ligation of two substrates at the expense of ATP hydrolysis

Question 46

The rate at which an enzymatic reaction proceeds depends on the concentrations of substrate, product, and active enzymes

Answer 46

Mag lesser ang substrate as time goes by habang ga taas ang ma produce na product

Question 47

________- Used in the living cell as a means of controlling enzymatic reactions

Answer 47

Enzyme inhibition

Question 48

Two types of enzyme inhibition

Answer 48

1. competitive inhibition 2.noncompetitive inhibition

Question 49

_____ -Caused by molecules that react directly with the active site of the enzyme

Answer 49

Competitive Inhibition

Question 50

_____-Øcan be reversed by an increase in substrate concentration

Answer 50

Competitive inhibition

Question 51

The competitive inhibition can be reversed by ___

Answer 51

increasing the substrate concentration

Question 52

Ømost competitive inhibitors are ______

Answer 52

substrate analogs

Question 53

Caused by molecules that bind to a region(s) of the enzyme outside the active site

Answer 53

Non-competitive inhibition

Question 54

Caused by molecules that bind to a region(s) of the enzyme outside the active site

Answer 54

Non-competitive inhibition

Question 55

_____ reversed by dilution or removal of the inhibitor

Answer 55

Non-competitive inhibition

Question 56

Chemical structure of noncompetitive inhibitors typically _____ from that of the substrate.

Answer 56

differs

Question 57

Regulation of Metabolic Reactions

Answer 57

1. Control of Enzyme Synthesis 2. Control of Enzyme Activity

Question 58

- Certain conditions that reduce protein synthesis generally - regulated at the molecular level by modulation of the rate of transcription of the gene encoding it (DNA is packaging; rate at which RNA is translated into proteins) Øenzymes are only synthesized when needed

Answer 58

Control of Enzyme Synthesis

Question 59

it is regulated by modulator molecules (interact with a part of the enzyme molecule )

Answer 59

Control of Enzyme Activity

Question 60

_____- - alters the tertiary structure of the enzyme thus changing the conformation of the active site

Answer 60

allosteric site

Question 61

interaction of the end product occurs in the allosteric site, making the end product an _____

Answer 61

allosteric inhibitor

Question 62

- several cat-ion cofactors act as allosteric activators for some enzymes

Answer 62

enzyme activation

Question 63

Two kinds of energy- yielding metabolic pathways in animal tissues:

Answer 63

. 1. aerobic metabolism 2. anaerobic metabolism

Question 64

____ -food molecules are completely oxidized to carbon dioxide and water by molecular oxygen; energy yield is far greater

Answer 64

Aerobic metabolism

Question 65

_____ - – food molecules are oxidized incompletely to lactic acid (lactate); absence of oxygen

Answer 65

anaerobic metabolism