Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biochem > Ex 2 > Flashcards

Ex 2 Flashcards

1
Q

What 2 ways can protein interact

A

-act as enzyme to alter chemical configuration or composition of bound molecule
-or interact without changing the chemical configuration or composition of bound molecule

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

What make up the 6 coordination bonds of iron?

A

-4 bind to nitrogen atoms in the porphyrin ring
-2 bonds perpendicular to the porphyrin ring

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

Describe the 2 perpendicular coordination bonds

A

-one is occupied by Nitrogen side chain of a conserved proximal His residue
-one is the binding site for O2

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

Fe2 binds O2 ______
Fe3 binds O2 _______

A

-reversibly
-Fe3 DOESNT

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

Describe globins

A

-protein family that binds oxygens
-have a highly conserved tertiary structure of 8 alpha helical segments bending into globin fold
-most function in O2 storage or transport

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

Describe myoglobin

A

-has single binding site for Oxygen
-153 residues, and one molecule of heme
-bends are named after the alpha helical segments that they’re connecting

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

Describe myoglobin His93 and HisF8

A

-93rd residue from the amino terminal end

F8:
8th residue in a alpha helix F

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does the Equilibrium Expression describe?

A

The reversible binding of a Protein to a Ligand
Forming protein ligand complex

P + L = PL

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

Hemoglobin transports…

A

Blood oxygen

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

Describe erythrocytes

A

Red blood cells that transport O2. They’re formed from hemocytoblasts
-main function is to carry hemoglobin

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

How much of arterial vs peripheral blood is saturated with O2

A

Arterial blood= 96%
Peripheral blood= 64%

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

What are hemocytoblasts

A

Precursor STEM cells

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

What is the T to R transition

A

T has low affinity for oxygen
R has high affinity for Oxygen

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

Hemoglobin undergoes…

A

Structure change on binding oxygen

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

What are the two conformations of hemoglobin

A

R state; O2 has a higher affinnity for hemoglobin
T state; more stable when O2 is absent, predominant conformation of deoxyhemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Hemoglobin has a _______ curve for oxygen and binds _____

A

Hybrid sigmoid binding
-cooperatively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Allosteric proteins and what types

A

Means the binding of a ligand to one site, affecting binding properties of another site on the same protein
Example: Hemoglobin

Types:
Modulators, homotropic, heterotropic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Define modulators, homotropic, and hetero tropic

A

Modulators: ligands that bind to an allosteric protein to induce a conformational change
Homotropic- normal ligand and modulators are identical
Heterotropic- modulator is a molecule other than the normal ligand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe MWC. Model

A

Concerted model
All subunits in same conformation
Ligand binds more tightly to the R state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe sequential model

A

Each subunit can be in either conformation. Equilibrium is altered as additional ligands are bound, progressively favoring the R state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Oxygen binding to hemoglobin is regulated by….

A

2,3. Biphosphoglycerate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Explain 2, 3 BPG

A

Example of heterotropic allosteric modulation
-binds distantly from the O2 binding site
- reduces affinity of hemoglobin for oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Leukocytes

A

White blood cells
-including macrophages and lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the 2 systems of the immune response

A

-humoral - directed to bacterial infections and viruses
-cellular - destroys infected host cells, parasites, and foreign tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Define antigen
- a virus, a bacterial cell wall, or a protein that can elicit an immune response. -antibodies or T cell receptors bind to an EPITOPE within the antigen
26
Define hapten
Small molecules that can elicit an immune response when its covalently attached to large proteins
27
Immunoglobulin G
- heavy and light chains having variable domains. - varibale domains associate to create 2 antigen binding sites - allows formation of an antigen antibody complex
28
Phagocytosis of antibody-bound viruses by Macrophages
-when Fc receptors bind an antibody pathogen complex, macrophages engulf that complex
29
Explain Western blots
1. Virus isolation 2. Protein suspension 3. SDS page 4. Electro transfer (membrane) 5. Antibody probing 6. Chemical-imaging
30
What does ELISA stand for?
Enzyme linked immunosorbent assay
31
In 1897 what did Eduard Buchner discover
-demonstrated cell-free yeast extracts could ferment SUGAR into ALCOHOL -showed fermentation was promoted by molecules that could continue to function after being removed from cells -these were given the name ENZYMES
32
Two most common types of ELISA’s?
Direct and sandwich
33
Catalytic/enzyme activity depends on…
Integrity of the native protein conformation
34
Range for enzyme mw
12000 to >1 million
35
Enzyme cofactors
1+ inorganic ions like Fe2+ , Mg2+ , Mn2+ , Zn2+
36
Enzyme coenzymes
Organic or metallorganic molecule that acts as transient carriers of functional groups
37
What are the seven enzyme classes
Oxidoreductase, transferase, hydrolase, lyase, isomerase, ligase, translocase
38
What is enzyme class: oxidoreductase
Transfer of e- (hydride or H atoms)
39
What is enzyme class: transferase
Group transfer
40
What is enzyme class: hydrolase
Hydrolysis (transfer of functional groups to water)
41
What is enzyme class: lyase
Cleavage of C-C, C-O, C-N , or other bonds by elimination, leaving double bonds or rings or addition of groups to double bonds
42
What is enzyme class: isomerase
Transfer of groups within molecules to yield isomeric forms
43
What is enzyme class: ligase
Formation of C-C, C-S, C-O, and C-N bonds by condensation rxn, coupled to cleavage of ATP or similar cofactor
44
What is enzyme class: translocase
Movement of molecules or ions across membranes or their separation within membranes
45
An enzyme that catalyzes the reaction S — > P also catalyzes ….
The reaction P ——> S -enzymes are NOT used up in the process -the equilibrium point is UNAFFECTED
46
Describe induced fit
Enzyme undergoes a conformational change when the substrate binds . This is induced by multiple weak reactions with the substrate to enhance catalytic properties
47
Enzymes must be complementary to the…
Reaction transition state
48
The full interactions between substrate and enzyme is formed only when…
Substrate reaches transition state
49
What is enzyme kinetics
Determining rate of reaction and how it changes in response to changes in experiments
50
When is Vmax observed
All the enzyme is present as the ES complex -further increases in [S] have no effect on rate
51
Michaelis Menten Equation
Rate equation for a one substrate catalyzed reaction
52
Michealis menten kinetics. (Hyperbolic dependence of V0 on S)
Km= [S] when V0= 1/2Vmax
53
General rate constant kcat
Kcat=Vmax/[Et]
54
Kcat=turnover number
Number of substrate molecules converted to product in a given unit of time on a single enzyme molecule when the enzyme is saturated
55
Specificity constant
Rate constant for the conversion of E+S to E+P
56
Enzyme inhibitors
Molecules that interfere with catalysis, slowing or halting enzymatic reactions
57
2 classes of enzyme inhibitors
Reversible: competitive, uncompetitive, mixed, noncompetitive Irreversible
58
Competitive inhibitor
Competes with the substrate for the active site. (reversible)
59
Uncompetitive inhibitors
Bind at a site distinct from the substrate active site. Unlike a competitive inhibitor, it binds only to the ES complex. (Reversible)
60
Line weaver Burke plot uncompetitive inhibition
Parallel lines Vmax decreases, Km decreases.
61
Line weaver Burke plot competitive inhibition
Lines intersect at the y axis. No change in Vmax, increase in Km.
62
Mixed inhibition
Binds at a site different from the substrate active site. Binds to either the E or ES complex. Type of reversible inhibition
63
Line weaver Burke plot mixed inhibition
Lines intersect to the left of the Y axis. V max decreases and the Km will increase
64
Noncompetitive inhibition
Mixed inhibition , a = a’ Affects Vmax NOT. Km Lines intersect at the X axis, dec V max, no Change in Km.
65
Irreversible inhibition
Can bind covalently with or destroy a functional Group on an enzyme that’s essential to enzyme activity. Or form a highly stable noncovalent association (Suicide inhibitors)
66
Induced fit in HEXOKINASE
When glucose and Mg ATP bind, the binding energy derived induces a conformational change in hexokinase to its active form
67
regulatory enzymes
They catalytically increase or decrease in response to certain signals, allowing the cell to meet changing needs for energy/biomolecules.
68
Types of regulatory enzyme modulation
Allosteric enzymes- function through reversible, noncovalent binding of allosteric modulators OR allosteric effectors (cofactors) Reversible covalent modification Binding of separate regulatory proteins Removal of peptide segments by proteolytic cleavage
69
The two types of conformational change of allosteric enzymes in response to modulator binding
Homotrophic- regulation where the substrate and modulator are identical Heterotrophic- regulation where the modulator is a molecule other than the substrate
70
Protein kinase
Catalyze attachment of phosphoryl groups to specific AA residues
71
Phosphoprotein phosphotase
Remove phosphoryl groups from the same target proteins
72
Zymogen
Inactive precursor that’s cleaved to form an active protease enzyme
73
Proprotein / proenzyme
Precursors that are cleaved to form other proteins
74
Carbohydrates
Aldehydes or ketones with at least 2 hydroxyl groups
75
Types of carbohydrates
Monosachharides- simple sugars with a single polyhydroxy aldehyde or ketone unit Oligosaccharides- short chains of monosaccharide joined by glycosidic bonds Disaccharides- oligosaccharides with 2 monosaccharide units Polysaccharides- sugar polymers with 10+ monosaccharide units
76
Epitope AKA
Antigenic determinant
77
define the FC and Fab regions.
N terminal fragments. Fab= antigen binding (recognizes antigen) Fc= crystallizable, well conserved AA seq. (Interacts with immune system)

Biochem (8 decks)

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