Chapter 6 Flashcards
1
Q
What is metabolism?
A
Totality of an organism’s chemical reactions
2
Q
What are the two types of metabolism?
A
- Anabolism
2. Catabolism
3
Q
Which type is the building-up process
A
Anabolism
4
Q
Which type is the breaking-up process?
A
Catabolism
5
Q
Each step is in the reaction is catalyzed by a
A
specific enzyme.
6
Q
What are the two types of metabolic pathways?
A
- Catabolic Pathways
2. Anabolic Pathways
7
Q
Differentiate anabolic pathway from catabolic pathway.
A
Catabolic- Release energy by breaking down complex molecules into simpler compounds
Anabolic- Consume energy to build complex molecules from simpler ones
8
Q
What is energy?
A
Ability to do work or bring about change
9
Q
How is energy measured?
A
Measured as heat content with units of calories or joules
10
Q
What unit of measurement is used for energy
A
1 cal = the quantity of heat required to raise 1g of water 1º C
11
Q
What are the two forms of energy?
A
- Kinetic
2. Potential
12
Q
Differentiate kinetic energy from potential energy.
A
Kinetic – energy in motion
Potential – energy that matter possesses because of its location or structure
13
Q
Give examples of kinetic energy.
A
Ex. light energy mechanical energy (motion) electrical thermal (heat)
14
Q
Give examples of potential energy.
A
Ex. chemical energy food, gas, wood gravitational energy from height above the earth
15
Q
exergonic?
A
Net release of free energy
16
Q
endergonic?
A
Absorbs free energy
17
Q
What does ATP stand for?
A
Adenosine triphosphate
18
Q
What are the three components of ATP?
A
- Adenine
- Phosphate
- Ribose
19
Q
When one phosphate of ATP is hydrolyzed, what is released?
A
-7.3 Kcalmol-1, Free energy
20
Q
Name some types of cellular work.
A
- Mechanical- muscular movement, movement of cellular flagella, nerve impules
- Transport- active transport
- Chemical- Anabolic processes
21
Q
What is an Enzyme?
A
It is a Catalytic proteins that speeds up chemical reactions
22
Q
What is a catalyst?
A
chemical agent that speeds up a reaction without being consumed by the reaction
23
Q
What are the components of an enzyme?
A
- Apoenzyme
2. Cofactor
24
Q
Which is the protein and non-protein part?
A
Apoenzyme- protein part
Cofactor-non protein part
25
The whole enzyme is called?
Holoenzyme
26
The region on the enzyme where the substrate binds is called?
active site
27
The reactant that an enzyme acts on is called?
substrate
28
The complex that is formed when enzyme binds to its substrate is called?
enzyme-substrate (ES) complex
29
The enzyme can lower the ___________ (EA) barrier?
Activation Energy
30
How does an enzyme lower the activation energy?
Orienting substrates correctly
Straining substrate bonds
Providing a favorable microenvironment
Covalently bonding to the substrate
31
What is activation energy?
the initial energy needed to start a chemical reaction.
32
Factors Affecting Rate of Enzyme Activity?
1. Temperature
2. Ph
3. Concentration of enzyme
4. Concentration of substrate
33
What is the effect of temperature on the rate of enzyme action?
- low temp -->low rate of reaction
- increasing temperature --> increasing rate of reaction
very high temperature -->denatures enzymes -->decreases rate of reaction
34
What is the effect of pH on the rate of enzyme action?
very low pH-->denatures enzymes-->low rate of reaction
- increasing pH-->increasing rate of reaction
- very high pH-->denatures enzymes-->decreases rate of reaction
35
What is the effect of enzyme concentration on the rate of enzyme action?
low enzyme conc-->low rate of reaction
- increasing enzyme conc-->increasing rate of reaction
- adding more enzyme-->no increase in the rate of reaction
36
What is the effect of substrate concentration on the rate of enzyme action?
- increasing substrate conc-->increasing rate of reaction
- adding more substrate-->no increase in the rate of reaction
- maximum rate is achieved when all enzymes bind with the substrate.
37
What are the two types of enzyme inhibitors?
1. Competitive inhibitor
| 2. Noncompetitive inhibitor
38
```
Consider a situation in which the enzyme is operating at optimum temperature and pH, and has been saturated with substrate. What is your best option for increasing the rate of the reaction?
A. Increase the pH.
B. Increase the temperature.
C. Increase the enzyme concentration.
D. Increase the substrate concentration
```
C, Increase the enzyme concentration.
39
A(n) _________ inhibitor has a structure that is so similar to the substrate that it can bond to the enzyme just like the substrate.
competitive
40
A(n) ________ inhibitor binds to a site on the enzyme that is not the active site.
noncompetitive
41
Usually, a(n) _______ inhibitor forms a covalent bond with an amino acid side group within the active site, which prevents the substrate from entering the active site or prevents catalytic activity.
irreversible
42
The competitive inhibitor competes with the substrate for the _______ on the enzyme.
active site
43
When the noncompetitive inhibitor is bonded to the enzyme, the shape of the ______ is distorted.
enzyme
44
Enzyme inhibitors disrupt normal interactions between an enzyme and its ________
substrate
45
You have added an irreversible inhibitor to a sample of enzyme and substrate. At this point, the reaction has stopped completely.
What can you do to regain the activity of the enzyme?
A. Removing the irreversible inhibitor should get the reaction working again.
B. The enzyme is inactive at this point. New enzyme must be added to regain enzyme activity.
C. Adding more substrate will increase the rate of reaction.
D. Adding more inhibitor should get the reaction up to speed again.
B. The enzyme is inactive at this point. New enzyme must be added to regain enzyme activity.
46
Which of these is exhibiting kinetic energy?
A. a person sitting on a couch while watching TV
B. an archer with a flexed bow
C. the high-energy phosphate bonds of a molecule of ATP
D. a rock on a mountain ledge
E. a space station orbiting Earth
E. a space station orbiting Earth
47
"Conservation of energy" refers to the fact that _____.
A. if you conserve energy you will not be as tired
B. the net amount of disorder is always increasing
C. energy cannot be created or destroyed but can be converted from one form to another
D. no chemical reaction is 100 percent efficient
E. the entropy of the universe is always increasing
C. energy cannot be created or destroyed but can be converted from one form to another
48
Chemical energy is a form of _____ energy.
```
A. heat
B. motion
C. potential
D. entropic
E. kinetic
```
C. potential
49
In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP?
```
A. redox
B. cellular respiration
C. anabolism
D. digestion
E. potentiation
```
B. cellular respiration
50
Which of these are by-products of cellular respiration?
```
A. carbon dioxide and water
B. ATP and carbon dioxide
C. heat, carbon dioxide, and water
D. glucose, carbon dioxide, and water
E. ATP, carbon dioxide, and water
```
E. ATP, carbon dioxide, and water
51
What type of reaction breaks the bonds that join the phosphate groups in an ATP molecule?
```
A. dehydration decomposition
B. anabolism
C. hydrolysis
D. dehydration synthesis
E. entropic
```
C. hydrolysis
52
In general, enzymes are what kinds of molecules?
```
A. lipids
B. carbohydrates
C. minerals
D. proteins
E.nucleic acids
```
D. proteins
53
Enzymes work by ____
A. increasing the potential energy difference between reactant and product
B. adding a phosphate group to a reactant
C. adding energy to a reaction
D. reducing EA
E. decreasing the potential energy difference between reactant and product
D. reducing EA
54
What name is given to the reactants in an enzymatically catalyzed reaction?
```
A. reactors
B. substrate
C. active sites
D. EA
E. products
```
B. substrate
55
Energy is observed in two basic forms: potential and kinetic. Which of the following correctly matches these forms with a source of energy?
A. the energy related to the height of a bird above the ground: kinetic energy
B. the heat released from a living organism: potential energy
C. the covalent bonds of a sugar molecule: potential energy
D. the motion of individual molecules: potential energy
E. the energy associated with a gradient of ions across a membrane: kinetic energy
C. the covalent bonds of a sugar molecule: potential energy
56
Which of the following is true of enzymes?
A. Enzymes increase the rate of chemical reaction by lowering activation energy barriers.
B. Enzyme function is increased if the 3-D structure or conformation of an enzyme is altered.
C. Nonprotein cofactors alter the substrate specificity of enzymes.
D. Enzyme function is independent of physical and chemical environmental factors such as pH and temperature.
E. Enzymes increase the rate of chemical reaction by providing activation energy to the substrate.
A. Enzymes increase the rate of chemical reaction by lowering activation energy barriers.
57
Increasing the enzyme concentration in an enzymatic reaction could overcome which of the following?
A. allosteric inhibition
B. competitive inhibition
C. saturation of the enzyme activity
D. denaturation of the enzyme
C. saturation of the enzyme activity
58
A. allosteric inhibition
B. competitive inhibition
C. saturation of the enzyme activity
D. denaturation of the enzyme
B. competitive inhibition
