Macromolecules (exam 2) Flashcards
(154 cards)
1
Q
functions of carbohydrates
A
- energy
- storage
- structure (matrix of connective tissue in our joints)
- cell recognition/communication: (AB blood type, this protein has a carbohydrate chain which is what distinguishes it from other types)
- modifies proteins affecting…. (glycosylating something can affect how it folds, how long it lasts…)
- structure/folding
- enzyme kinetics: Vmax and Km
- Turnover/degradation: turnover can be faster or slower depending on the carbohydrate chain
2
Q
alpha 1-4 glycosidic bond
A
- more common
- easily broken down for energy and modified for storage
3
Q
examples of alpha 1-3 glycosidic bonds
A
- sucrose
- starch
4
Q
what kinds of bonds does glycogen have?
A
- both alpha 1-4 and alpha 1-6 glycosidic bonds
- this gives glycogen its characteristic branched structure
5
Q
glycogen
A
the primary carbohydrate storage molecule
6
Q
what kinds of bonds does lactose have?
A
Beta 1-4 glycosidic bond
7
Q
how are common alpha glycosidic bonds processed?
A
they’re hydrolyzed by amylase
8
Q
What does lactose require?
A
- the beta bond of lactose requires lactase
9
Q
where is lactase only produced?
A
in the cells of mucosa of the small intestine
10
Q
when does lactose intolerance occur?
A
when the body stops producing lactase
11
Q
Lactose intolerance can be ______ or ______
A
temporary
genetic/developmental
12
Q
_____ is a common filler in pharmaceuticals
A
lactose
13
Q
where is amylase produced?
A
pancreas
saliva
14
Q
how are sugar alcohols formed?
A
by the reduction of the carbonyl group
15
Q
when do sugar alcohols occur?
A
polyol pathway
16
Q
Sorbitol function
A
- sugar alcohol
- used for storage
- can be metabolized forward to fructose
- can be metabolized back to glucose
17
Q
Sorbitol is an _____
A
effective osmole
18
Q
Inositol function
A
- signaling
- myelin attachment
- nerve function
19
Q
what are the forms of cyclic carbohydrates?
A
alpha or beta isomers
20
Q
how is glucose transported into cells?
A
by either
- insulin dependent transporters
- insulin independent transporters
21
Q
importance of insulin independent transporter proteins?
A
they maintain the basal level of glucose required for cell survival
22
Q
what happens to excess glucose?
A
it enters the polyol pathway
23
Q
where can you find a high percentage of insulin-independent transporters?
A
- kidney
- retinal
- nerve tissue (retina)
24
Q
where can you find insulin dependent transporters?
A
- liver
25
what is the liver efficient in doing?
- handling high levels of blood sugar and bringing it back down
26
insulin independent transporters
- no inhibition
| - doesn't bind insulin
27
insulin dependent transporters?
- limited inhibition
- binds insulin (limited)
- shoots up and down according to blood sugar levels
28
how are acidic sugars formed?
by the oxidation of the 6' OH group or the 1' carbonyl group to a carboxyl group
29
where does formation of acidic sugars occur?
- in many tissues
| - highest in the liver, kidney, and RBC
30
what does the liver use acidic sugar formatio for?
for conjugation (to change solubility)
31
example of an acidic sugar
Glucuronic acid
32
Functions of Glucuronic acid
- used as a detoxifying agent
- conjugates with molecules to increase solubility, transport, or excretion
- makes it easier to get rid of toxins and waste
33
dietetic candy
uses sorbitol as a sweetener. goes right through the digestive system
34
Bilirubin
byproduct of RBCs being broken down
35
how are amino sugars formed?
by the replacement of an OH group with an NH2
36
examples of amino sugars and their functions
glucosamine and galactosamine
| - compose the matrix in connective tissue
37
what increases the structural nature of amino sugars?
beta bonds between alternating amino sugars
| *other organisms do this in beta bonds but humans always use alpha bonds
38
hyaluronic acid
- weakest crosslinking, much more fluid
| - proper
39
Chondroitin sulfate
- cartilage
| - supplements for joint health because it's the building block for the matrix of cartilage
40
matrix for connective tissue
- where the cells live in fluid, gel or a solid environment
| - cells secrete/make the matrix
41
purposes of glycosylation
1. modify/regulate protein function (change their Vmax and Km with their enzymes)
2. stabilization of proteins in the serum (antibody Fc fragment)
3. may aid in initial protein folding
4. aids in cell recognition and binding to membrane proteins (type A, B, O blood type)
5. increases hydration of molecules (mucus has a lot of carbohydrate moieties in it)
6. involved in stabilizing structure like connective tissue
42
how do you do fatty acid nomeclature
of carbons: # of double bonds + the position of the double bond
43
eicosanoids
- diverse group of hormones and signaling molecules
44
how are eicosanoids produced
by the oxidation of fatty acids-particularly arachidonic and similar molecules
45
what are the primary enzymes involved in eicosanoid synthesis?
- cyclooxygenase (COX)
| - lipoxygenases (LOX)
46
what does COX produce
prostaglandins and thromboxanes (prostanoids)
47
what does LOX produce
leukotrienes and lipoxins
48
what does the COX pathway result in
molecules with a cyclical structure
49
Prostanoids
- locally active hormones/signals which are rapidly degraded
- type of eicosanoids
50
what do prostanoids often exhibit
- opposing functions which are kept in balance during homeostasis and can change/be induced during pathological conditions
51
functions of prostanoids
- inflammation mediation
- cardiovascular homeostasis
- reproductive function
52
what does the LOX pathway produce
- complex molecules without a cyclic component
53
Acylglycerol/glycerides
- ester of glycerol and fatty acids that occurs naturally as fats and fatty oils
54
how do phospholipids start out?
- as diacylglycerol with a phosphate group covalently bonded to the third site of the glycerol molecule
55
how are phospholipids formed
- presence of phosphate group changes the diacylglycerol to phosphatidic acid (same thing as phospholipid)
56
functions of phospholipids
1. membrane structure (phospholipid bilayer)
2. signaling
3. fatty reservoir for hormone production (COX pathway)
57
fatty acid chains
diacylglycerol
58
Phosphatidylcholine
- component of HDLs
- increases fluidity
- yields fatty acids for signaling
- (example of phospholipid modification)
59
Phosphatidylinositol
- high concentration in nerve cells
- cell attachment/organization
- signaling, PIP2
60
where is cholesterol
embeds in the hydrophobic region
61
function of cholesterol
- stabilizes the transition state (fluidity)
62
Steroidogenic pathway
1. cholesterol entering the mitochondria and undergoing conversion to pregnenolone
2. then can turn into other things
63
once cholesterol turns into pregnenolone, what happens?
can be converted into
- mineralocorticoids
- glucocorticoids
- estrogens/androgens
64
can steroids enter any cell?
yes
65
what happens if a receptor is present when the steroid enters the cell
the complex becomes a transcription factor
66
what happens if when the steroid enters the cell, there's no receptor?
- steroid broken down
67
what happens if there's an excess of steroid
stored in the membrane
68
what happens when there's increased sterols in the membrane
- increased membrane rigidity
- makes membrane less fluid (can't transport things)
- decreases cell reactivity
69
bile salts
- function
- where is it produced
liver produces bile salts to aid in the emulsification of fat in the small intestine
70
how are bile salts formed
bile acids interact with Na+
71
what are fat soluble vitamins based on?
cholesterol
72
list the fat soluble vitamins
A, D, E, and K
73
Fat soluble vitamins
- essential nutrients with either the vitamin or the precursor needing to come from a dietary source
74
functions of proteins
1. structure
2. hormones/signaling
3. NTs
4. blood clotting
5. viscosity
6. antibodies
7. transport
8. enzymes
75
hi
hi
76
what is the point of variation between AAs
R group
77
how is the rate of reaction impacted:
| unlimited substrate
increases
78
how is the rate of reaction impacted:
| pH
affects charge and reactivity of active site, best rate at optimal pH
79
how is the rate of reaction impacted: temperature
rate increases until denaturation occurs
80
the reaction continues until _______
all the enzyme is in the enzyme-substrate complex
81
Vmax is the
point of saturation
82
holoenzyme (functional)
apoenzyme + prosthetic group
83
cofactors
- inorganic
- usually metal ions
- Mg2+, Fe2+. Zn2+
- required by certain enzymes
84
example of a cofactor
- ATPases require a Mg2+ cofactor to put stress on the high energy bonds
85
Coenzymes
- organic molecules
| - such as vitamins and carrier molecules
86
example of a coenzyme
- the complex, pyruvate dehydrogenase requires thiamine (B1) to act as an electron sink for the carboxylation of pyruvate
87
prosthetic group
A tightly bound, specific non-polypeptide unit required for the biological function of some proteins.
88
apoenzyme
the protein part of an enzyme
89
holoenzyme
- an active enzyme and can perform the catalytic activity.
90
why are apoenzymes important
they are responsible for the specificity of enzymes to their substrates
91
are apoenzymes active? why or why not?
Apoenzymes alone are not active enzymes; they must bind to an organic or inorganic cofactor in order to be activated
92
how are holoenzymes made
- After binding to a cofactor, apoenzyme forms a holoenzyme
93
competitive inhibitors
- resemble the substrate and bind to the active site
94
noncompetitive inhibitors
- bind to an allosteric site
| - alter the shape of or access to the active site
95
is inhibition reversible?
yes inhibition can be reversible or irreversible
96
reversible inhibition
the enzyme remains functional after removal of the inhibitor
97
irreversible inhibition
the inhibitor permanently alters the enzyme leaving it nonfunctional
98
explain substrate level inhibition
- can occur when an enzyme has 2 binding sites, active and allosteric, for the substrate
- these 2 sites would have different Km values, with the allosteric binding occurring as [S] increases
99
what does binding at the allosteric site do?
decreases the binding/conversion at the active site
100
what does a different kM mean??
different affinities
101
Vmax
maximum turnover rate for enzyme
102
what catalyzes the first step in the detoxification of alcohol
alcohol dehydrogenase
103
what's an example of toxin mitigation
detoxification of alcohol
104
explain the steps of detoxification of alcohol
1. alcohol
2. acetaldehyde by alcohol dehydrogenase
3. acetate
105
acetaldehyde
- highly toxic molecule exerting negative effects on the liver and CNS, and complex effects on the cardiovascular system
106
how does toxin mitigation of alcohol work?
- by slowing the conversion to the intermediate, the most negative effects can be somewhat mitigated
107
product level inhibition
- product binds a allosteric site on the enzyme to slow reaction
108
what is product level inhibition involved in? explain how
metabolic regulation
| - the product inhibition ensures that glucose will not be dedicated to ATP production unless the cell is utilizing it
109
metabolic regulation
physiological mechanism by which the body takes in nutrients and delivers energy as required
110
list 2 examples of product level inhibition
1. hexokinase
| 2. many Krebs cycle enzyme
111
what do the Km and Vmax tell us?
basic information about the enzyme's function
112
what does Km refer to?
- affinity of enzyme for substrate
| - the [S] at 1/2 Vmax
113
what does lower Km mean?
higher affinity
114
what does higher km mean?
lower affinity
115
what does Vmax give you insight on?
the capacity of the [E] to handle fluctuations in [Substrate[
116
what is this: when all the enzyme is in the ES complex
Vmax
117
isoenzymes
- catalyze the same reaction but due to minor structural changes, have different activity levels
118
where are hexokinases found?
- in most tissues
| - considered the maintenance enzyme
119
where is glucokinase primarily found
in the liver
120
glucokinase is technically a...
very specific form of hexokinase
121
medical application of isoenzymes
- because they're tissue specific, their presece in the blood is indicative of damage to a specific tissue type
- CREATINE PHOSPHOKINASE (CPK, CK)
122
CPK1
brain and lugns
123
CPK2
heart
124
CPK3
skeletal muscle
125
functions of nucleic acids
1. genetic information
2. direct protein synthesis
3. energy
4. NTs
126
what are nucleic acids made up of?
nucleotide monomers
127
2 examples of nucleic acids
DNA and RNA
128
what is the monomer of DNA
AMP
129
what are the basic components of a nucleotide
nitrogenous base
ribose sugar
phosphate group
130
list the pyridimines
cytosine
uracil (RNA)
thymine (DNA)
131
list the purines
Guanine
| Adenosine
132
which is larger: purines or pyrimidines
purines
133
in nucleotides: where is the phosphate group bonded to?
the 5' carbon of a sugar
134
in nucleotides: where is the nitrogenous base bonded to?
1' carbon of sugar
135
list the nitrogenous bases
```
cytosine
uracil
thymine
guaine
adenine
```
136
composition of nucleotide
phosphate group, 5 carbon sugar, nitrogenous base
137
Ribose
- sugar for RNA
| - 5-carbon simple sugar
138
Deoxyribose
- sugar for DNA
| - has the same 5-carbon formula as that of ribose sugar but loses an oxygen atom
139
_______ reaction forms DNA
Condensation
140
how is DNA made?
nucleotides bind so that the 3' OH group of one attaches to the 5' phosphate of the other
141
In a DNA chain, the polymer will only attach new monomers....
to the 3' end
142
list the DNA forms
B DNA
A DNA
Z DNA
143
B DNA
- most common
| - right handed helix
144
A DNA
- shorter
- more dense
- right handed helix
- RNA DNA complexes
- double stranded RNA regions
145
Z DNA
- longer
- stretched out
- left handed helix
- increased methylation
- shut down
146
list the ribonucleic acid forms
```
mRNA
rRNA
tRNA
hnRNA
sRNA
```
147
mRNA
coded message that directs peptide synthesis
148
rRNA
stabilizes mRNA in the ribosome
149
tRNA
transfers AA to ribosome for peptide construction
150
hnRNA
- heterogenous nuclear RNA
- unedited RNA
- contains introns that have to be removed
151
snRNA
- small nuclear RNA
| - forms complexes with proteins forming snRNPs
152
snRNPs
perform splicing of hnRNAs to produce mRNAs
153
energy molecules
contain high energy bonds
| - nucleic acid modification
154
NT
- adenosine is simply the nucleoside w/o the phosphate group
- nucleic acid modification
