Enzymes PPT

Question 1

the capacity to do work

Answer 1

energy

Question 2

How do cells obtain energy?

Answer 2

1. sun

2. organic/ inorganic compounds

Question 3

List the 2 types of energy.

Answer 3

1. kinetic energy

2. potential energy

Question 4

chemical energy stored in bonds; concentration gradient across a membrane

Answer 4

potential energy

Question 5

light; sound; movement of atoms and molecules; muscle contraction

Answer 5

kinetic energy

Question 6

List 4 forms of energy.

Answer 6

1. chemical
2. electrical
3. mechanical
4. radiant or electromagnetic

Question 7

form of energy stored in bonds of chemical substances

Answer 7

chemical energy

Question 8

form of energy which results from movement of charged particles

Answer 8

electrical energy

Question 9

form of energy directly involved in moving matter

Answer 9

mechanical energy

Question 10

form of energy which travels in waves (e.g. visible light, ultraviolet light, and x-rays)

Answer 10

radiant or electromagnetic energy

Question 11

Explain the flow of energy.

Answer 11

one way:

• starts with the sun (lost)
• transferred to environment
• transferred to organisms (gain)
• transferred back to environment (loss)

Question 12

reaction that occurs whenever chemical bonds are formed, rearranged, or broken

Answer 12

chemical reaction

Question 13

reaction pathway term:

substances that enter a reaction

Answer 13

substrates

Question 14

What are substrates also called?

Answer 14

reactants/ precursors

Question 15

reaction pathway term:

any substance that forms between the start and conclusion of the pathway

Answer 15

intermediate

Question 16

reaction pathway term:

substances left at the end of the reaction

Answer 16

end products

Question 17

reaction pathway term:

proteins that speed up specific reactions

Answer 17

enzymes

Question 18

reaction pathway term:

assist enzymes

Answer 18

cofactors

Question 19

chemical reaction in which small molecules are used to build bigger ones

Answer 19

anabolic

Question 20

chemical reaction in which large molecules are broken down into smaller products

Answer 20

catabolic

Question 21

the total of reactions taking place inside the cell

Answer 21

metabolism

Question 22

chemical reaction in which smaller particles are bonded together to form larger, more complex molecules molecules

Answer 22

synthesis reaction

Question 23

Give an example of a synthesis reaction.

Answer 23

Amino acids are joined together to form a protein molecule.

Question 24

Synthesis reactions are also called ___ or ___ reactions when water is produced.

Answer 24

condensation/ dehydration synthesis

Question 25

chemical reaction in which bonds are broken in larger molecules, resulting in smaller, less complex molecules

Answer 25

decomposition reaction

Question 26

Give an example of a decomposition reaction.

Answer 26

Glycogen is broken down to release glucose units.

Question 27

Decomposition reactions are also called ___ reactions when water is split.

Answer 27

hydrolysis

Question 28

The patterns of chemical reactions can be either ___ or ___.

Answer 28

constructive, | degradative

Question 29

reactions where electrons are exchanged

Answer 29

oxidation-reduction ("redox") reactions

Question 30

part of a redox reaction: | gain of electrons; electron acceptor

Answer 30

reduction

Question 31

part of a redox reaction: | loss of electrons; electron donor

Answer 31

oxidation

Question 32

Where can oxidation-reduction reactions be observed?

Answer 32

in cellular reactions such as cellular respiration

Question 33

energy flow in chemical reactions: | energy input required; product has more energy than starting substances

Answer 33

endergonic

Question 34

energy flow in chemical reactions: | energy released; products have less energy than starting substances; occurs spontaneously

Answer 34

exergonic

Question 35

Reactions move towards ___.

Answer 35

equilibrium

Question 36

When does chemical equilibrium occur?

Answer 36

if neither a forward nor reverse reaction is dominant

Question 37

What prevents equilibrium?

Answer 37

"disappearance" of a product

Question 38

Do reactions run at the same/different rates in forward and reverse directions?

Answer 38

the same rate

Question 39

In forward and reverse reactions, are the rates of product and reactant formation equal/different?

Answer 39

equal

Question 40

What does ATP stand for?

Answer 40

Adenosine Tri-Phosphate

Question 41

nucleotide that acts like cell's currency; directly powers chemical reactions in cells; energy form immediately useable by all body cells

Answer 41

Adenosine Tri-Phosphate (ATP)

Question 42

Energy from ATP is stored when phosphate groups are added onto ADP in ___ reactions.

Answer 42

phosphorylation

Question 43

in this process ADP and a free phosphate form ATP, storing energy in a form the cell can use

Answer 43

ADP phosphorylation

Question 44

in this process the last phosphate is broken off; ATP becomes ADP and a free phosphate; energy released is used to power a reaction

Answer 44

ATP hydrolysis

Question 45

ATP links what reactions?

Answer 45

endergonic to exergonic

Question 46

Reactions release and store energy in ___.

Answer 46

ATP

Question 47

All cells depend on the ___ in ATP.

Answer 47

potential energy

Question 48

Metabolic reactions in cells are ___ reactions.

Answer 48

coupled

Question 49

Burning glucose directly is an ___ method of acquiring energy. Why?

Answer 49

inefficient, | most energy lost as heat

Question 50

The electron transport chain is an ___ method of acquiring energy. Why?

Answer 50

efficient, | works like a staircase

Question 51

method of acquiring energy in which molecules give and accept electrons in steps; ATP is produced

Answer 51

electron transport chain

Question 52

Which parts of the electron transport chain have the highest and lowest amounts of energy?

Answer 52

highest energy: start of chain, | lowest energy: end of chain

Question 53

What type of reactions does the electron transport chain use to ultimately produce ATP?

Answer 53

oxidation-reduction

Question 54

Exergonic reactions are spontaneous and can occur on their own, why haven't they all occurred already?

Answer 54

requires an activation energy input to break the bonds and start the reaction

Question 55

anything that speeds up a reaction

Answer 55

catalyst

Question 56

In biology, catalysts ___ the activation energy and ___ the speed of a reaction making the reaction more likely to occur.

Answer 56

lower, | increase

Question 57

example of a biological catalyst

Answer 57

enzyme

Question 58

proteins; do not make anything happen that couldn't happen on its own (just faster); not used up or altered; same works in forward and reverse reaction; are reaction specific; usually end in -ase

Answer 58

enzymes

Question 59

An enzyme has a specific ___ to bind to a specific substrate.

Answer 59

shape

Question 60

In an enzyme, the substrate fits into the ___.

Answer 60

active site

Question 61

groove in the enzyme's surface

Answer 61

active site

Question 62

must be present for enzyme to work; act as helpers; often oxidized or reduced; not consumed

Answer 62

cofactors

Question 63

Organic cofactors are ___.

Answer 63

coenzymes

Question 64

What factors affect enzyme activity?

Answer 64

temperature, | pH

Question 65

Small increases in temperature increases ___ and reaction rates.

Answer 65

molecular collisions

Question 66

High temperatures disrupt bonds and ___.

Answer 66

destroy the shape of the active site

Question 67

What is the ideal pH range for most enzymes?

Answer 67

6-8 (neutral)

Question 68

Enzyme regulation occurs through ___.

Answer 68

allosteric regulators

Question 69

allosteric regulators: | binds to the enzyme at a site other than the active site called the ___

Answer 69

allosteric site

Question 70

Allosteric repression is also called ___.

Answer 70

non-competitive inhibition

Question 71

Allosteric regulators alter the shape of the active site to either allow or inhibit substrate binding through allosteric ___ and ___.

Answer 71

activation, | repression

Question 72

special type of allosteric repression; product of the reaction is the allosteric repressor

Answer 72

feedback inhibition

Question 73

Feedback inhibition is also called ___.

Answer 73

negative feedback

Question 74

blocks or occupies active site; prevents binding of substrates

Answer 74

competitive inhibition

Question 75

rarer form of feedback in which product activates the pathway leading to its own production

Answer 75

positive feedback

Question 76

example of positive feedback

Answer 76

blood clotting and child birth

Question 77

List some everyday uses of enzymes.

Answer 77

``` found in detergents, used to make breads, used to make wine and beer, used to make cheese, meat tenderizers break down muscle tissue, fruit enzymes breakdown proteins ```