Biochemistry > Chapter 21 > Flashcards

Chapter 21 Flashcards

(90 cards)

Start Studying
1
Q

Lock & key

A

enzyme has a rigid shape

only substrate of a specific shape can bind with the acive site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

Induced-Fit model

A

enzymes are flexible, fit like a glove

when substrate contacts enzyme the enzyme will change the shape of the active site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

non-protein part of conjugated enzyme

small organic molecules or Inorganic ions

organic molecules are called co-enzymes or co-substrates

A

cofactor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

biochemically active conjugated enzyme

made of apoenzyme and cofactor

A

holoenzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

enzyme that catalyzes transfer of a functional group from one molecule to another

Two major subtypes:
–Transaminases - catalyze transfer of an amino group to a substrate
–Kinases - catalyze transfer of a phosphate group from adenosine triphosphate (ATP) to a substrate

A

transferase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

allosteric enzyme

A

enzyme with 2 active sites (one for substrate and one for regulatory enzyme)

Binding of molecules at the regulatory site causes changes in the overall three dimensional structure of the enzyme:
–Some regulators increase enzyme activity – activators
–Some regulators decrease enzyme activity - inhibitors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

Fat soluble vitamins

A

Vitamins A, D, E, K
•Involved in plasma membrane processes
•More hydrocarbon like with fewer functional groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q
  • Four forms of it: a-, b-, g- and d-
  • Alpha-tocopherol is the most active biological active form of this
  • Peanut oils, green and leafy vegetables and whole grain products are the sources of this
  • Primary function: Antioxidant – protects against oxidation of other compounds
A

vitamin E

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

prescription drugs that inhibit enzyme activity

  • All have structures containing a four-membered Beta-lactam ring fused with a five-membered thiazolidine ring
  • Selectively inhibits transpeptidase by covalent modification of serine residue
  • Transpeptidase catalyzes the formation of peptide cross links between polysaccharides strands in bacterial cell walls
A

penicillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

extremeophiles

A

organisms that thrive in extreme environments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

enzyme that catalyzes hydrolysis

involves addition of a water molecule to a bond to cause bond breakage

central to digestion

5 types:

lipase - hydrolysis of lipids (ester linkage)

protease- hydrolysis of protein (peptide linkage)

nuclease - hydrolysis of nucleic acid (sugar-phosphate linkage)

carbohydrase - hydrolysis of carbs (glycosidic linkages)

phosphatases - hydrolysis of phosphoester linkages

A

hydrolase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Intake of 100 mg/day saturates all body tissues - Excess vitamin is excreted

Humans, monkeys, apes and guinea pigs need this

Involved in metabolism of certain amino acids

It is a co-substrate in the formation of structural protein collagen

water soluble vitamin

A

vitamin C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

vitamin A

A

Has role in vision. Combines with opsin protein to form the visual pigment rhodopsin which further converts light energy into nerve impulses that are sent to the brain

Regulates Cell Differentiation: A process in which immature cells change to specialized cells with function

Maintenance of the healthy of epithelial tissues via epithelial tissue differentiation.

Reproduction and Growth: In men, it participates in sperm development. In women, normal fetal development during pregnancy requires this.

derived from beta-carotene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

effect of pH on enzyme activity

A

As pH increases, enzyme activity increases until it reached optimal pH. Then enzyme activity decreases as pH increases
•Drastic changes in pH can result in denaturation of proteins
•Optimum pH: pH at which enzyme has maximum activity
•Most enzymes have optimal activity in the pH range of 7.0 - 7.5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

vitamin E

A
  • Four forms of it: a-, b-, g- and d-
  • Alpha-tocopherol is the most active biological active form of this
  • Peanut oils, green and leafy vegetables and whole grain products are the sources of this
  • Primary function: Antioxidant – protects against oxidation of other compounds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
  • An organic compound essential for proper functioning of the body
  • Must be obtained from dietary sources because human body can’t synthesize them in enough amounts

Needed in micro and milligram quantities

  • Enough can be obtained from balanced diet
  • Supplements may be needed after illness

2 types: water soluble and fat soluble

A

vitamins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

–An enzyme will catalyze a particular reaction for only one substrate
–This is most restrictive of all specificities (not common)

A

absolute specificity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

hydrolase

A

enzyme that catalyzes hydrolysis

involves addition of a water molecule to a bond to cause bond breakage

central to digestion

5 types:

lipase - hydrolysis of lipids (ester linkage)

protease- hydrolysis of protein (peptide linkage)

nuclease - hydrolysis of nucleic acid (sugar-phosphate linkage)

carbohydrase - hydrolysis of carbs (glycosidic linkages)

phosphatases - hydrolysis of phosphoester linkages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

ACE inhibitor

A

prescription drugs that inhibit enzyme activity

  • block conversion of Angiotensin I to angiotensin II in the blood.
  • Angiotensin II is an octapeptide hormone that increases blood pressure via constriction of blood vessels.

This blocks that and thus reduces BP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

effect of enzyme concentration on enzyme activity

A

•At a constant substrate concentration, enzyme activity increases with increase in enzyme concentration
–The greater the enzyme concentration, the greater the reaction rate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

lyase

A

enzyme that involves double bond either in reactant or product (but does not involve oxidation or reduction)

4 types:

hydratase - addition of H20 molecule (double bond in reactant)

dehydratase - removal of H20 to make double bond

deaminase - removal or amino group to make double bond

decarboxylase - removal of CO2 group to make double bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

enzyme that catalyzes oxidation, reduction or dehydrogenation (H removal)

requires a coenzyme that is either oxidized or reduced as the substrate in the reaction

A

oxidoreductase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

enzymes

A

proteins that act as catalysts for biochemical reactions

not consumed in reactions

globular proteins

affected by temperature, pH, substrate concentration and enzyme concentration

6 major classifications

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

cipro

A

prescription drug that inhibits enzyme activity

an antibiotic

•Considered the best broad-spectrum antibiotics because it is effective against skin and bone infections as well as against infections involving the urinary, gastrointestinal, and respiratory systems
•It is the drug of choice for treatment of traveler’s diarrhea
Bacteria are slow to acquire resistance to this

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
active site
small part of enzyme's structure that is involved in catalysis place where substrate binds to enzyme Formed due to folding and bending of the protein. Some enzymes have more than one of these
17
group specificity
–Involves structurally similar compounds that have the same functional groups. e.g. amine, OH, phosphate
17
proteolytic enzyme
enzymes that are generated in an inactive form and then, when needed, converted to their active form. hydrolyze peptide bonds in proteins most digestive and blood-clotting enzymes are these their inactive forms are called zymogen
19
covalent modification of enzymes
A process in which enzyme activity is altered by covalently modifying the structure of the enzyme –Involves adding or removing a group from an enzyme Most common - addition and removal of phosphate group type of irreversible inhibition
19
prescription drug that inhibits enzyme activity exhibit antibiotic activities
sulfa drugs
20
cofactor
non-protein part of conjugated enzyme small organic molecules or Inorganic ions organic molecules are called co-enzymes or co-substrates
20
–Involves a particular type of bond irrespective of the structural features in the vicinity of the bond –Considered most general of enzyme specificities –E.g., Phosphatases: Hydrolyze phosphate–ester bonds in all types of phosphate esters
linkage specificity
21
enzyme that involves double bond either in reactant or product (but does not involve oxidation or reduction) 4 types: hydratase - addition of H20 molecule (double bond in reactant) dehydratase - removal of H20 to make double bond deaminase - removal or amino group to make double bond decarboxylase - removal of CO2 group to make double bond
lyase
23
oxidoreductase
enzyme that catalyzes oxidation, reduction or dehydrogenation (H removal) requires a coenzyme that is either oxidized or reduced as the substrate in the reaction
24
enzyme with 2 active sites (one for substrate and one for regulatory enzyme) Binding of molecules at the regulatory site causes changes in the overall three dimensional structure of the enzyme: –Some regulators increase enzyme activity – activators –Some regulators decrease enzyme activity - inhibitors
allosteric enzyme
25
enzyme inhibitor
•a substance that slows down or stops the normal catalytic function of an enzyme by binding to it. 2 types: competitiveand non competitive
26
composed of protein and non-protein parts
conjugated enzymes
27
enzymes are flexible, fit like a glove when substrate contacts enzyme the enzyme will change the shape of the active site
Induced-Fit model
27
Vitamins A, D, E, K •Involved in plasma membrane processes •More hydrocarbon like with fewer functional groups
Fat soluble vitamins
28
Has role in vision. Combines with opsin protein to form the visual pigment rhodopsin which further converts light energy into nerve impulses that are sent to the brain Regulates Cell Differentiation: A process in which immature cells change to specialized cells with function Maintenance of the healthy of epithelial tissues via epithelial tissue differentiation. Reproduction and Growth: In men, it participates in sperm development. In women, normal fetal development during pregnancy requires this. derived from beta-carotene
vitamin A
29
ligase
enzyme that forms a new bond and consumes ATP 2 types: synthetase - formation of new bond between 2 substrates carboxylase - formation of new bond between substrante and CO2
29
Function: components of many coenzymes –Serve as temporary carriers of atoms or functional groups in redox and group transfer reactions associated with metabolism water soluble vitamin
B vitamins
31
composed only of proteins
simple enzymes
32
sulfa drugs
prescription drug that inhibits enzyme activity exhibit antibiotic activities
32
prescription drugs that inhibit enzyme activity * block conversion of Angiotensin I to angiotensin II in the blood. * Angiotensin II is an octapeptide hormone that increases blood pressure via constriction of blood vessels. This blocks that and thus reduces BP
ACE inhibitor
33
noncompetitive inhibitor
Enzyme that does not compete with the substrate for the same active site •Binds to the enzyme at a location other than active site and it changes the active site's shape so a reaction cannot take place Reversible
33
B vitamins
Function: components of many coenzymes –Serve as temporary carriers of atoms or functional groups in redox and group transfer reactions associated with metabolism water soluble vitamin
34
–Involves structurally similar compounds that have the same functional groups. e.g. amine, OH, phosphate
group specificity
35
enzymes that are generated in an inactive form and then, when needed, converted to their active form. hydrolyze peptide bonds in proteins most digestive and blood-clotting enzymes are these their inactive forms are called zymogen
proteolytic enzyme
37
Enzyme that competes with the substrate for the same active site •Will have similar charge & shape. Binds to the active site to block the substrate so a reaction cannot take place Reversible
competitive inhibitors
38
enzyme that forms a new bond and consumes ATP 2 types: synthetase - formation of new bond between 2 substrates carboxylase - formation of new bond between substrante and CO2
ligase
40
linkage specificity
–Involves a particular type of bond irrespective of the structural features in the vicinity of the bond –Considered most general of enzyme specificities –E.g., Phosphatases: Hydrolyze phosphate–ester bonds in all types of phosphate esters
41
Vitamin K
* Two major forms; \_1 and \_2 * \_1 found in dark green, leafy vegetables * \_2 is synthesized by bacteria that grow in colon * Dietary need supply: ~1/2 synthesized by bacteria and 1/2 obtained from diet * Active in the formation of proteins involved in regulating blood clotting
43
A way of regulating enzyme activity A process in which activation or inhibition of the first reaction in a reaction sequence is controlled by a product of the reaction sequence. •Regulators of a particular allosteric enzyme may be: –Products of entirely different pathways of reaction within the cell –Compounds produced outside the cell (hormones)
feedback control
44
simple enzymes
composed only of proteins
46
inactive precursor of proteolytic enzyme
zygomens
47
enzyme has a rigid shape only substrate of a specific shape can bind with the acive site
Lock & key
48
stereochemical specificity
enzyme only catalyzes a specific isomer (L or D)
50
absolute specificity
–An enzyme will catalyze a particular reaction for only one substrate –This is most restrictive of all specificities (not common)
51
penicillin
prescription drugs that inhibit enzyme activity * All have structures containing a four-membered Beta-lactam ring fused with a five-membered thiazolidine ring * Selectively inhibits transpeptidase by covalent modification of serine residue * Transpeptidase catalyzes the formation of peptide cross links between polysaccharides strands in bacterial cell walls
52
A process in which enzyme activity is altered by covalently modifying the structure of the enzyme –Involves adding or removing a group from an enzyme Most common - addition and removal of phosphate group type of irreversible inhibition
covalent modification of enzymes
53
small part of enzyme's structure that is involved in catalysis place where substrate binds to enzyme Formed due to folding and bending of the protein. Some enzymes have more than one of these
active site
55
effect of temperature on enzymes
* Higher temperature results in higher kinetic energy which causes an increase in number of reactant collisions, therefore there is higher activity. * Optimum temperature: Temperature at which the rate of enzyme catalyzed reaction is maximum * Optimum temperature for human enzymes is 37ºC (body temperature) * Increased temperature (high fever) leads to decreased enzyme activity
57
extremozyme
A microbial enzyme that is active at conditions that would inactivate human enzymes as well as enzymes present in most other organisms. These are if high interest to industrial chemists bc industrial processes require extreme temp, pressure and pH
58
A microbial enzyme that is active at conditions that would inactivate human enzymes as well as enzymes present in most other organisms. These are if high interest to industrial chemists bc industrial processes require extreme temp, pressure and pH
extremozyme
60
Irreversible inhibitor
inactivates enzymes by forming a strong covalent bond with the enzyme’s active site. –The structure is not similar to enzyme’s normal substrate –The inhibitor bonds strongly and increasing substrate concentration does not reverse the inhibition process Enzyme is permanently inactivated
61
vitamins
* An organic compound essential for proper functioning of the body * Must be obtained from dietary sources because human body can’t synthesize them in enough amounts Needed in micro and milligram quantities * Enough can be obtained from balanced diet * Supplements may be needed after illness 2 types: water soluble and fat soluble
62
transferase
enzyme that catalyzes transfer of a functional group from one molecule to another Two major subtypes: –Transaminases - catalyze transfer of an amino group to a substrate –Kinases - catalyze transfer of a phosphate group from adenosine triphosphate (ATP) to a substrate
64
holoenzyme
biochemically active conjugated enzyme made of apoenzyme and cofactor
65
isomerase
enzyme that catalyzes rearrangement of functional groups. only one substrate 2 types: racemase - conversion of D-isomer to L-isomer mutase - transfering functional group from one position to another in the same molecule
67
Enzyme that does not compete with the substrate for the same active site •Binds to the enzyme at a location other than active site and it changes the active site's shape so a reaction cannot take place Reversible
noncompetitive inhibitor
68
zygomens
inactive precursor of proteolytic enzyme
70
competitive inhibitors
Enzyme that competes with the substrate for the same active site •Will have similar charge & shape. Binds to the active site to block the substrate so a reaction cannot take place Reversible
71
Two forms active in the body: Vitamin \_2 and \_3 •Sunshine Vitamin: Synthesized by UV light from sun •It controls correct ratio of Ca and P for bone mineralization (hardening) •As a hormone it promotes Ca and P absorption in intestine
vitamin D
72
protein part of conjugated enzyme
apoenzyme
73
enzyme substrate complex
•Intermediate reaction species formed when substrate binds with the active site 2 types: Lock & Key (enzyme has rigid shape) Induced-Fit (enzyme is flexible, fits like a glove)
75
enzyme that catalyzes rearrangement of functional groups. only one substrate 2 types: racemase - conversion of D-isomer to L-isomer mutase - transfering functional group from one position to another in the same molecule
isomerase
76
feedback control
A way of regulating enzyme activity A process in which activation or inhibition of the first reaction in a reaction sequence is controlled by a product of the reaction sequence. •Regulators of a particular allosteric enzyme may be: –Products of entirely different pathways of reaction within the cell –Compounds produced outside the cell (hormones)
77
enzyme only catalyzes a specific isomer (L or D)
stereochemical specificity
78
vitamin C
Intake of 100 mg/day saturates all body tissues - Excess vitamin is excreted Humans, monkeys, apes and guinea pigs need this Involved in metabolism of certain amino acids It is a co-substrate in the formation of structural protein collagen water soluble vitamin
79
•a substance that slows down or stops the normal catalytic function of an enzyme by binding to it. 2 types: competitiveand non competitive
enzyme inhibitor
80
apoenzyme
protein part of conjugated enzyme
81
effect of substrate concentration on enzyme activity
Enzyme activity increases as substrate concentration increases until it reaches saturation, then it remains constant •Substrate Concentration: At a constant enzyme concentration, the enzyme activity increases with increased substrate concentration. •Substrate saturation: the concentration at which it reaches its maximum rate and all of the active sites are full
82
•Intermediate reaction species formed when substrate binds with the active site 2 types: Lock & Key (enzyme has rigid shape) Induced-Fit (enzyme is flexible, fits like a glove)
enzyme substrate complex
83
inactivates enzymes by forming a strong covalent bond with the enzyme’s active site. –The structure is not similar to enzyme’s normal substrate –The inhibitor bonds strongly and increasing substrate concentration does not reverse the inhibition process Enzyme is permanently inactivated
Irreversible inhibitor
85
proteins that act as catalysts for biochemical reactions not consumed in reactions globular proteins affected by temperature, pH, substrate concentration and enzyme concentration 6 major classifications
enzymes
86
organisms that thrive in extreme environments
extremeophiles
87
vitamin D
Two forms active in the body: Vitamin \_2 and \_3 •Sunshine Vitamin: Synthesized by UV light from sun •It controls correct ratio of Ca and P for bone mineralization (hardening) •As a hormone it promotes Ca and P absorption in intestine
88
* Two major forms; \_1 and \_2 * \_1 found in dark green, leafy vegetables * \_2 is synthesized by bacteria that grow in colon * Dietary need supply: ~1/2 synthesized by bacteria and 1/2 obtained from diet * Active in the formation of proteins involved in regulating blood clotting
Vitamin K
89
prescription drug that inhibits enzyme activity an antibiotic •Considered the best broad-spectrum antibiotics because it is effective against skin and bone infections as well as against infections involving the urinary, gastrointestinal, and respiratory systems •It is the drug of choice for treatment of traveler’s diarrhea Bacteria are slow to acquire resistance to this
cipro
90
conjugated enzymes
composed of protein and non-protein parts

Biochemistry (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions