Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BMS 102 > Final Exam > Flashcards

Final Exam Flashcards

1
Q

What are the three classifications of carbohydrates?

A
  • Monosaccharides
  • Disaccharides
  • Polysaccharides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Name the three monosaccharides

A

Glucose, Fructose, Galactose

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

Name the three disaccharides and their monosaccharide components

A

Maltose: Glucose+Glucose
Lactose: Glucose+Galactose
Sucrose: Glucose+Fructose

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

Name the three polysaccharides

A

Starch
Glycogen
Cellulose

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

Aldehyde functional group

A

Hydrogen, Carbonyl, Carbon

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

Keton functional group

A

Carbon, Carbonyl, Carbon

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

Monosaccharide with an ____ group is an aldose while a monosaccharide containing a ____ is a ketose

A

Aldehyde; Ketone

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

What is another name for aldotriose?

A

Glyceraldehyde

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

What is another name for ketotriose

A

Dihydroxyacetone

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

What are enantiomers

A

Non-super imposable mirror images

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

What are diastereoisomers

A

Not mirror images

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

How are D and L forms determined?

A

By the -OH group on the chiral C atom furthest from the carbonyl end (aka the most oxidized end) that determines D or L configuration. If the -OH is on the right then it is D- and if the OH is on the left it is L

Nearly all carbohydrates are members of the D family

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

What are epimers?

A

Sugars that are diastereoisomers and only differ in configuration at a single asymmetric center

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

What are the two possible configurations of monosaccharides?

A

D and L

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

What is the general formula of a carbohydrate?

A

(CH2O)n

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

An aldehyde plus an alcohol forms what?

A

A hemiacetal

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

A ketone plus an alcohol forms what?

A

A hemiaketal

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

Alpha is ___ and Beta is ____

A

down; up

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

What is an anomer?

A

An isomer that differs in arrangement of bonds around the hemiacetal carbon

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

Why does cyclisation of D-glucose give 2 isomers, alpha-D-glucose and beta-D-glucose

A

When carbonyl group of C1 of D-glucose reacts with C-5 hydroxyl group, a new chiral carbon is created (C1). In the alpha-isomer of the cyclic sugar, the C1 hydroxyl group is below the ring; in the beta-isomer, the C1 hydroxyl group is above the ring

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

Maltose linkage

A

Derived from the condensation of glucose and glucose which forms alpha 1,4 glycosidic linkages

Full linkage alpha-d-glucose(1,4)-alpha-d-glucose

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

Lactose linkage

A

Derived from the condensation of galactose and glucose to form a B 1,4 glycosidic linkage

Full linkage:
Beta-d-galactose-(1,4)-alpha-D-glucose

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

Sucrose linkage; anything special about sucrose?

A

Derived from the condensation of glucose and fructose but the anomeric C of both sugars is used in the formation of the glycosidic bond
*Is a non-reducing sugar b/c anomeric carbons of both glucose and fructose are used – therefore sucrose does not have a free –OH and is not a reducing sugar

Alpha (1,2) glycosidic bond

Alpha-D-glucose-(1,2)-beta-D-fructose

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

Amylose; composed of & linkages

A

a linear, unbranched chain of alpha-D-glucose units (up to 4000 units) - alpha-1,4 glycosidic bonds
-has both a reducing and nonreducing end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Amylopectin; composed of and linkages

A

Has a glucose backbone – branches leading to one reducing and many non-reducing ends

Branches are attached to the main chain from the C1 of one alpha-D-glucose to the C6 hydroxyl group of alpha-D-glucose in the main chain - alpha-1,6 glycosidic bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Glycogen linkages

A

A highly branched molecule structurally similar to amylopectin but has more numerous alpha-1,6 glycosidic linkages (thus higher molecular weight)
-also consists of a single reducing end and numerous non-reducing ends

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the linkage in cellulose?

A

Beta 1,4

  • cellulose consists of a linear chain of several hundred to thousands of B-D-glucose units
  • cellulose is the most abundant polysaccharide
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Outcomes of Glycolysis

A

4 ATP Produced (net gain of 2)

2 Pyruvate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Outcomes of TCA

A

2 ATP

2 Acetyl CoA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Outcomes of ETC

A

34 ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Which step of glycolysis is the Hexose Stage?

A

The first half of glycolysis is the hexose stage
Step 1-4 ; Phosphorylation of glucose by hexokinase or glucokinase

Glucose 6 phosphate isomerase catalyzes the isomeraization
of of G6P

Phosphofructokinase phosphorylates F6-P

Clevage of F-1,6 P by fructose bisphosphate aldolase to produce DHAP and G3P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What does the first phase of glycolysis produce? Second?

A

G3P and two pyruvates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the net reaction of glycolysis

A

Glucose + 2 ADP + 2 NAD+ + 2 Pi —-> 2 Pyruvate + 2 ATP + 2 NADH + 2 H+ + 2 H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What are the three possible fates for pyruvate?

A

In yeast (anaerobic fermentation):

Glucose ->pyruvate->ethanol

In muscle (anaerobic respiration):
Glucose -> pyruvate -> lactate
In muscle (aerobic respiration)
Glucose -> pyruvate -> acetyl CoA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Two step process to convert pyruvate to ethanol

A
  • pyruvate is decarboxylated to acetaldehyde by pyruvate decarboxylase
  • Acetaldehyde is reduced to ethanol by NADH and alcohol dehydrogenase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Equation to convert pyruvate to ethanol

A

Glucose + 2 ADP +2 Pi + 2 H+ —->

2 Ethanol + 2 CO2 +2 ATP + 2 H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What enzyme do mammals lack that yeast do not that allows them to convert pyruvate to ethanol

What happens to pyruvate instead?

A
  • Pyruvate decarboxylase

- Pyruvate converted to lactate where it is then transported to the liver for gluconeogensis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is the equation for converting pyruvate to lactate

A

Glucose + 2 ADP +2 Pi ——-> 2 Lactate + 2 ATP + 2 H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are the three irreversible steps of glycolysis?

A

1,3, and last
Hexokinase
PFK1
Pyruvate kinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Inhibitors and activators of PFK1

A
  • High ATP = allosteric inhibitor

- High AMP and ADP - allosteric activators

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Which steps of glycolysis use ATP

A

Step 1
Glucose -> G6P
Step 3
Fructose-6-phosphate to fructose 1,6 bisphosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Which steps of glycolysis produce ATP

A

1,3-bisphophoglycerate ->3 phosphoglycerate

Phosphoenolpyruvate to pyruvate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Pyruvate (the end product of glycolysis) must be converted to ____ before it enters the CAC

A

Acetyl CoA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Each molecule of pyruvate is transported across the _____ mitochondrial membrane into the _______

A

Inner; matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

_______ transports pyruvate and H+ from the inter membrane space to the interior space of the mitochondrion

A

Pyruvate translocase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What enzyme converts pyruvate to acetyl coA; what is the equation?

How many ATP produced?

A

Pyruvate dehydrogenase
Pyruvate + CoA-SH + NAD+ ——> Acetyl CoA + CO2 + H+ + NADH

2 NADH (3 ATP per NADH) = 6 ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Which steps are oxidation steps in the TCA cycle?

A

4; 3,4,6,8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

End products of TCA cycle

A

3 NADH, 1 FADH, and 1 GTP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What are the irreversible reactions of the TCA cycle

A

Step 1: Oxidation of acetyl CoA where 2 acetyl CoA condense with 4 OAA to form citrate
Step 3: first oxidation step and formation of alpha ketoglutarate
Step 4: Second oxidation and formation of succinyl CoA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Equation of the citric acid cycle

A

Acetyl CoA + 3NAD+ + FAD + GDP + Pi + 2H2O —–> CoA-SH + 3NADH + 3H+ + FADH2 + GTP + 2CO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

How many ATP are produced from the CAC

A

24 total

3 NADH ->9 ATP (3 ATP for each NADH)
1 FADH2 ->2 ATP (2 ATP for each FADH2)
1 GTP -> 1 ATP
Total: 12 ATP per acetyl CoA -> (x2 Acetyl CoA)

=24

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Gains of the catabolism of glucose through glycolysis and the citric acid cycle

A

Oxidation of 2 molecules of acetyl CoA by the citric acid cycle and oxidative phosphorylation produces 24 molecules of ATP
Glycolysis generates: 2 NADH (6 ATP) and 2 ATP = 8ATP
Pyruvate dehydrogenase complex generates 6 ATP

Total of 38 moles of ATP per mole of glucose oxidised to CO2 and water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

ETC

A

The Electron Transport chain is a series of electron carrier in the inner membrane of the mitochondria. Electrons are passed form NADH to oxygen (the final acceptor), moving protons from the matrix to the inter membrane space. FADH also donates electrons to the chain, releasing hydrogen ions into the inter membrane space. Eventually, the high H+ concentration in the inter membrane space causes some of the ions to flow down the concentration gradient and back into the matrix through ATP synthase, producing ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What are the two mobile electron carriers in the ETC?

A

Coenzyme Q (between complexes I and III) and Cytochrome C (between complexes III and IV)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Chemiosmosis

A

The movement of ions across a semipermeable membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Gluconeogenesis

A

The conversion of pyruvate to glucose from non carbohydrate precursors

*noncarb precursors are first converted to pyruvate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What are the three noncarb precursors

A

Lactate, amino acids, and glycerol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Net equation for gluconeogenesis

A

2Pyruvate + 2NADH + 4ATP + 2GTP + 6H2O + 2H+ —>Glucose + 2NAD+ + 4ADP + 2GDP + 6Pi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Which steps of glycolysis are in the triose stage?

A

The second half

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

The Pentose Phosphate pathway; produces?

A

-Divided into oxidative and non oxidative stages

  • After conversion to glucose 6-phosphate, glucose can enter the PPP (aka hexose monophosphate shunt)
  • PPP runs parallel to glycolysis

Produces NADPH and forms ribose-5-phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

In what tissues is the PPP active?

A

Ones that synthesize fatty acids or steroids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

PPP Oxidative stage

A

Glucose 6-phosphate + 2NADP+ + H2O ———> Ribulose 5-phosphate + 2 NADPH + CO2 + 2H+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

PPP Non oxidative stage

A

Ribulose 5-phosphate —-> 2 Fructose 6-phosphate + Glyceraldehyde 3-Phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Glycogenolysis

A

Degradation of glycogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Which end are glucose residues removed from during phosphorolysis

A

the non reducing end

(only acts on alpha-1,4-linkages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Glycogen ____ stops ____ residues from a branch point with ____ bond and resulting _____ is further degraded by a _______ enzyme

A

Phosphorylase; 4; alpha 1-6; limit dextrin; glycogen-debranching

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

______ activity of the glycogen deb ranching enzyme catalyzes the relocation of _____ glucose residues to allow the deb ranching enzymes to _________

A

Glucanotransferase; 3; remove the remaining alpha 1,6 linked glucose molecule to produce a free glucose molecule and an elongated unbranched chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What is the end product of glycogenolysis

A

Glucose-1-phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What happens to glucose-1-p after glycogenolysis?

A

converted to G6P by phosphoglucomutase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What are the steps to incorporate one G6P into glycogen?

A

***Glucose converted to G6P by hexokinase

G6P –> G1P (Phosphoglucomutase)
G1P —> UDP-Glucose (UDP-Glucose pyrophosphorylase)
-UDP-Glucose -> Glycogen (glycogen synthase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Role of insulin in blood glucose and glycogen

A
  • fed strate
  • B cells
  • Increases the rate of glucose transport into muscle and adipose tissue via GLUT 4 glucose transporter
  • stimulates glycogen sythesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Role of glucagon in blood glucose and glycogen

A
  • Alpha cells
  • low blood glucose (fasted state)
  • Stimulates glycogen degradation
  • Only liver cells are rich in glucagon receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

Adrenaline and role in blood glucose and glycogen

A
  • A catecholamine
  • flight or flight
  • stimulates breakdown of glycogen to G1P (which is converted to G6P)
  • Increased G6P levels increase the rate of glycolysis in muscle and glucose release to the bloodstream from the liver
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

Glycogen phosphorylase is ______ in the _____ state and glycogen synthase is more active in the _______ state

A

more active; phosphorylated; dephosphorylated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

4 Parts of an amino acid

A 
side chain (R)
Amino group (NH2)
H
Carboxyl group (COOH)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Two stages of amino acid degradation and where?

A

-In the liver
Stage 1: The alpha amino nitrogen must be removed (via transamination and
oxidative deamination reactions) – amino group eventually ends up as urea
Stage 2: remaining carbon skeletons are then shuttled into central metabolic pathways (eg. Citric acid cycle)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

Result of transamination

A

A new keto acid and glutamate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

Which enzyme catalyzes the interconversion of aspartate and alpha ketoglutarate to OAA and glutamate

A

Aspartate transaminase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

What enzyme is often used as a clinical diagnostic test for liver function

A

Aspartate transaminase (AST)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

Which enzyme catalyses the interconversion of alanine and alpha- ketoglutarate to pyruvate and glutamate

A

Alanine transaminase (ALT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

Which enzyme is useful for screening for liver associated problems

A

ALT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

What compound do transamination and oxidative deamination generate in large amounts

A

Ammonium ion - NH4+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

What are the 3 enzymes of the urea cycle that are located in the cytosol

A

argininosuccinate synthase, arginase and argininosuccinate lyase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

What are the two enzymes of the urea cycle that are located in the mitochondria

A

ornithine transcarbamoylase and carbamoyl phosphate synthase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

Overall reaction of the urea cycle

A

CO2 + NH4+ + 3ATP + aspartate + 2H2O —> urea+2ADP+2Pi +AMP+PPi +fumarate+5H

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

In every turn of the urea cycle ___ nitrogens are eliminated 1 from ____ and 1 from ____

A

2; oxidative deamination of glutamate; alpha amino group of aspartate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

What is the committed step in the urea cycle

A

Biocarbonate ion and NH4 reacting to form carbamoyl phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

Fate of ketogenic amino acids

A

Metabolized to acetoacetate or acetate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

fate of glycogenic amino acids

A

Pyruvate or TCA intermediates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

What is the definition of a hormone

A

A substance that is synthesized and secreted by specialized cells and carried via the blood circulation to target cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

Name 4 sites of hormone secretion

A

Pineal gland, Hypothalamus, Pancreas, Thyroid Gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

What are the three categories of hormones

A

Autocrine
Paracrine
Endocrine

93
Q

What is an autocrine hormone

A

A hormone that acts upon the secretory cell

94
Q

What is a paracrine hormone

A

A hormone that acts on adjacent cells

95
Q

What is an endocrine hormone

A

A hormone that acts on target cells at a distance (usually travels via the bloodstream to distance target cells)

96
Q

What are the five classifications of hormones

A 
Peptides
Proteins
Steroids
Amino Acid Derivatives
Eicosanoids
97
Q

Peptide hormones are synthesized as protein precursors known as

A

Preprohormones

98
Q

Once a preprohormone is produced what happens

A

It is targeted to the Golgi where a signal sequence is removed to form a pro hormone where it is then processed into the active hormone and packaged into secretory vesicles

99
Q

What is an example of a peptide hormone

A

Insulin

100
Q

Describe insulin biosynthesis

A
  • Preproinsulin is synthesized as a random coil on membrane associated ribosomes
  • After membrane transport the signal peptide sequence is cleaved off, resulting in proinsulin which folds into a stable conformation
  • Disulfide bond formation occurs
  • Connecting sequence (C-peptide) is cleaved out by endopeptidases to leave the mature insulin molecule
101
Q

Proinsulin processing: Where does trypsin cleave?

A
  1. C-peptide and A chain
  2. C-Peptide and B-chain
  3. Carboxypeptidase B-like enzyme removal of basic amino acid residues
102
Q

Effects of insulin on carbohydrate metabolism

A
  • increase glucose uptake in muscle and adipose tissue
  • Increase glycolysis in muscle and adipose
  • increase glycogen synthesis in muscle, adipose, and liver
  • inhibits glycogenolysis and gluconeogenesis
  • increase glucose oxidation in Pentose, Phosphate Pathway
103
Q

Direct negative feedback

A

where rate of hormone production/secretion is related to the blood concentration of metabolite ex. insulin and blood glucose control

-Insulin acts on target cells (e.g. muscle) ultimately to decrease blood glucose concentration, a change in blood glucose alters insulin secretion from pancreatic beta-cells

104
Q

What effects does insulin have on lipid metabolism?

A
  • Inhibits rate of lipolysis (lipid breakdown) in adipose tissue
  • Stimulates fatty acid (FA) and triacylglycerol (TG) synthesis in adipose tissue & liver
  • Increases VLDL synthesis in liver
  • Increases lipoprotein lipase + uptake of blood TG’s in adipose tissue.
  • May decrease rate of FA oxidation in liver
105
Q

What effect does insulin have on protein metabolism

A

In general insulin encourages protein synthesis rather than amino acid oxidation.

  • Increases transport of some amino acids (aa’s) into muscle, adipose, liver & other cells.
  • Increases protein synthesis in muscle, adipose & liver cells.
  • Decreases rate of protein breakdown in muscle
106
Q

Where are steroid hormones derived from?

A

The gonads, the adrenal cortex, and the placenta in pregnancy

107
Q

What are the five major categories of steroid hormones?

A
  • Progestins
  • glucocorticoids,
  • mineralocorticoids -androgens
  • estrogens
108
Q

What is the precursor of all other steroid hormones?

A

Cholesterol; it is converted to pregnenolone via a two step process

109
Q

After pregnenolone is produced what happens

A

It is converted to progesterone by oxidation of the hydroxyl group to a ketone and isomeraization of a double bond

110
Q

In the synthesis of steroid hormones what is the branch point between glucocorticoids and androgens

A

17-hydroxyprogesterone

111
Q

Where is cortisol synthesized?

A

In the adrenal cortex in response to signals from the adrenocorticotropic hormone (ACTH)

112
Q

What is the primary role of cortisol? Other roles?

A

to increase survival during periods of stress when glucocorticoid
secretion can increase by almost 10-fold

  • Mobilize energy through glucose homeostatic mechanisms (raise blood glucose)
  • Suppress the immune system
  • Modulation of skeletal processes
  • “Fight or flight hormone”
113
Q

What are the two groups of hormones derived from the amino acid tyrosine

A
  • Thyroid hormones

- Catechlamines

114
Q

What are two thyroid hormones made by modifying tyrosine residues in the protein thyroglobulin

A
  • Thyroxine

- Triiodothyronine

115
Q

Effects of thyroid hormones on metabolism

A
  • Produce a general increase in the metabolism of carbohydrates, fats, proteins
  • Increase oxygen consumption and heat production directly in heart, kidney, liver, and muscle
116
Q

Effects of thyroid hormones on growth and development

A
  • Important for normal response to the thyroid hormone calcitonin
  • Skeletal bone development
  • Growth and maturation of the CNS
117
Q

Catecholamines are also known as ____ and ____

A

Neurohormones and neurotransmitters

118
Q

Where are catecholamines mainly produced

A

In the adrenal medulla

119
Q

What are the most common catecholamines

A

Epinephrine
Norepinephrine
Dopamine
Dihydroxy-phenylalanine

120
Q

What are some of the actions of catecholamines

A
  • Important in the fight or flight response
  • Exert a powerful stimulant effect on the heart: increase heart rate, and increase force of contraction
  • Convert energy stores to freely available fuel: (glycogen to glucose and stored fat to free fatty acids)
121
Q

4 Families of eicosanoids

A

Prostaglandins
Thromboxanes
Leukotrienes
prostacyclin

122
Q

What are eicosanoids derived from?

A

Arachidonic acid

123
Q

What are prostaglandins

A

-“Hormone-like”
unsaturated carboxylic acids
consisting of a 20-carbon skeleton that contains a 5 ring carbon
-Exert effects on cells that produce them and other cells of the body

124
Q

Actions of prostaglandins

A
  • Stimulation of smooth muscle
  • Regulation of steroid biosynthesis
  • Inhibition of gastric secretion & hormone-sensitive lipases
  • Inhibition and stimulation of platelet aggregation
  • Regulation of nerve transmission
  • Sensitization to pain
  • Mediation of inflammatory response
125
Q

Membrane receptors

A

-Embedded in the cell membrane.
-Often are G-protein coupled receptors with 7- transmembrane domains
-Usually are receptors which respond to
neurotransmitters, peptides and proteins.

126
Q

Intracellular receptors

A
  • Present in the cytoplasm or nucleus

- Respond to hydrophobic signal molecules such as steroids and thyroid hormones

127
Q

What are the two hormonal mechanisms

A

-Enzyme activation or inhibition via second messengers – epinephrine, glucagon and insulin work in this way

-Stimulation of the synthesis of particular proteins, by direct action through activation of
specific genes in the cell nucleus

128
Q

Peptide and protein hormones tend to use which hormone mode of action?

A

-Use of second messengers ex. cyclic AMP

129
Q

Involvement of a peptide hormone in the control of cellular function starting and continuing with:

A

-the synthesis of the hormone in its endocrine cell
-release into bloodstream in response to specific
stimulus
-binding to a specific target cell receptor
-intracellular second messenger release
-biological effect on target tissue
-feedback control mechanism acting to down-regulate
hormone producing cell

130
Q

Which hormone mode of action do steroid hormones use?

A

-Direct action on the activation of specific genes

~the hormone crosses the plasma membrane and binds to specific receptor proteins in the cytoplasm

  • The receptor hormone complex dimerizes and migrates to the nucleus where it interacts with specific DNA sequences called hormone responsive elements
  • Hormones in this class include: steroids, thyroid hormones, and hormonal forms of vitamin D
131
Q

How does the liver help to remove hormones from the bloodstream?

A

Metabolizes by conjugating with water soluble metabolites (glucuronide)
-secreted to bile, excreted in feces or can enter bloodstream and be excreted by the kidneys

132
Q

How do the kidneys help to remove hormones from the blood stream?

A

By inactivating them and excreting the constituent amino acids directly into the urine

133
Q

How are steroid hormones eliminated

A

Mammalian cells lack the ability to completely degrade steroid compounds. As a result most become conjugated through their hydroxyl groups to glucuronate or sulfate and are eliminated in the urine

134
Q

What are the three key elements of nucleic acids

A

heterocyclic nitrogenous base, sugar and phosphate(s)

In RNA the sugar is ribose whereas in DNA the sugar is 2-deoxyribose

135
Q

Nucleic acid bases can be divided into what two categories

A

Purines and Pyrimidines

136
Q

Purines

A

Adenine and Guanine

137
Q

Pyrimidines

A

Cytosine
Thymine
Uracil (RNA)

138
Q

Nucleotide components

A

Base + sugar + phosphate

139
Q

Nucleoside components

A

Base + sugar

140
Q

Nucleotides are ____ acids

A

Strong

141
Q

Bases in nucleotides can exist as ______ which are structural isomers differing only in _________

A

Tautomers; location of H atoms and double bonds

142
Q

What are the two important features of polynucleotides

A
  1. Sense or directionality

2. Individuality

143
Q

What is the secondary structure of nucleic acids?

A

Two strand helix stabilized by hydrogen bonding between bases on opposite strands if bases were paired up in a particular way

144
Q

DNA base pairs?

A

A and T

C and G

145
Q

Salvage pathways

A

Synthesizing nucleotides that have become available in the diet or from the enzymatic breakdown of nucleic acids

146
Q

Purine nucleotide degradation leads to production of _____

A

Uric acid

147
Q

Purines ->uric acid steps

A

Nucleotidases convert nucleotides to nucleosides; purine nucleoside phosphorylase (PNP) catalyzes removal of ribose-1-phosphate moiety; free bases oxidized by xanthine dehydrogenase to uric acid

148
Q

In some mammals uric acid is degraded further into…?

A

Allantoin which can then be further oxidized into allantoic acid…some animals can even catabolize it further into urea

149
Q

What happens when humans have an excessive accumulation of uric acid?

A

Gout; which arises from overproduction of purine nucleotides, impaired uric acid excretion from kidneys, or both

150
Q

De novo synthesis of pyrimidine ring involves 2 precursors

A

Aspartate and carbamoyl phosphate

151
Q

What are lipids

A

Naturally occurring molecules that are grouped together based on being soluble in non polar solvents
-may be hydrophobic or amphipillic

152
Q

What are the two essential lipids?

A
  • alpha-linolenic acid (n-3)

- linoleic acid (n-6)

153
Q

What are the four main groups of lipids

A

Fatty acids, Glycerides, Non-glycerides, Complex lipids

154
Q

What are the two fatty acids

A
  • saturated

- unsaturated

155
Q

What are the 3 fatty glycerides

A

Monoglycerides
Diglycerides
Triglycerides

156
Q

What are the 3 nonglycerides

A
  • Sphingolipids
  • Steroids
  • Waxes
157
Q

What is an example of a complex lipid

A

Lipoprotein

158
Q

What are three functions of lipids?

A
  • Energy
  • Cell membrane and structure
  • Hormones
159
Q

What is the end product of beta oxidation?

A

Acetyl CoA

160
Q

Saturated fats have a ______ melting point than unsaturated fatty acids of the same C length

A

High

161
Q

Most double bonds are in the ____ formation

A

Cis

162
Q

Delta system

A

-Numbers from the carboxyl end to the first unsaturated carbon

163
Q

N minus system

A

Numbers from the terminal methyl carbon to the first
unsaturated carbon, “substracts” those carbons, and places these numbers in parentheses

α-Linolenic acid – 18:3 (n-3)
#3 from methyl carbon
CH3-CH2-CH=CH-CH2-CH=CH-CH2-CH=CH(CH2)7COOH
164
Q

Omega system

A

Numbers from the terminal methyl carbon to the first unsaturated carbon

α-Linolenic acid -- 18:3 ω3
#3 from methyl carbon
CH3-CH2-CH=CH-CH2-CH=CH-CH2-CH=CH(CH2)7COOH
165
Q

Common name, IUPAC for C18:0

A

Stearate; Stearic Acid

Octadeconate

166
Q

Common name and IUPAC name for C18:1 n-9

A

Oleate ; 9-Octadecenoic acid

Cis Δ9 octadeconoate

167
Q

Common name and IUPAC for C18:3

A

Linoleate

Octadeconoate

168
Q

4 Chemical reactions of fatty acids

A

Esterification, Acid Hydrolysis, Saponification; Reaction at double bond (hydrogenation)

169
Q

Product of Esterification

A

Carb acid + Alcohol —> Ester + Water

170
Q

Acid hydrolysis

A

*Reverse esterification (producing fatty acids from esters)
Rxn also called hydration

Ester + water –> Carb acid + alcohol

171
Q

Saponification

A

The base-catalyzed hydrolysis of an ester
The product – ionised salt (soap)
Soap - Long uncharged hydrocarbon tail & a negative charged terminus they form micelles that dissolve oil and dirt particles

172
Q

Even numbered eicosanoids are ____ inflammatory while _____ numbered eicosanoids are anti inflammatory

A

Pro inflammatory; even

173
Q

Thromboxane

A

Stimulates constriction of blood vessels and platelet aggregation

174
Q

Prostacyclin

A

Inhibits platelet aggregation and causes dilation of blood vessels

175
Q

What are the two classes of glycerides?

A
  • Neutral glycerides

- Phosphoglycerides

176
Q

Phosphoglycerides

A
  • Phosphate (polar) head

- Nonpolar tail

177
Q

Sphingolipids

A

Spingosine backbone (contains a long chain, and a nitrogen containing alcohol)

  • Amphipathic
  • Structural components of cellular membranes
178
Q

Sphingomyelins

A
  • Located throughout the body

- Important for structural components of nerve cell membranes

179
Q

3 Glycosphingolipids

A
  • Cerebrosides
  • Sulfatides
  • Gangliosides
180
Q

Cerebrosides

A
  • contain the sphingosine backbone attached to a fatty acid and a carbohydrate (most often glucose or galactose).
  • Those that contain several carbohydrates are called gangliosides

Ex: Glucocerebroside

181
Q

Galactocerebroside

A

found almost exclusively in the membranes of brain cells

182
Q

Sulfatides

A

derived from galactocerebroside that contain a sulfate group

183
Q

What is cholesterol synthesized from?

A

Acetic acid

184
Q

What does HDL do?

A

Carry cholesterol out of the blood for excretion

185
Q

What does LDL do?

A

Carry cholesterol to body cells for use

186
Q

Atherosclerosis

A

Occluding of blood vessels leading to HBP, coronary heart disease and others

187
Q

What are the 4 classes of complex lipids

A

Chylomicrons
VLDL
LDL
HDL

188
Q

Chylomicrons

A

carry triglycerides from intestine to other tissues

189
Q

Very low density lipoprotein (VLDL

A

bind triglycerides synthesised in liver & transport to adipocytes for storage

190
Q

Low density lipoprotein (LDL

A

bind cholesterol & transport it to peripheral tissues – regulate cholesterol levels

191
Q

High density lipoprotein (HDL)

A

bound to plasma cholesterol & transport cholesterol from peripheral tissues to the liver

192
Q

What are the four steps of beta oxidation?

A

Oxidation
Hydration
Oxidation
Split

193
Q

What are the three ketone bodies?

A

Acetone
Acetoacetic acid
beta-hydroxybutyric acid

194
Q

Which ketone cannot be used?

A

Acetone; it is excreted in the urine or exhaled

195
Q

Under normal conditions the brain uses ____ as its source of energy. Under fasting conditions the brain uses ____ as its source of fuel

A

Glucose; ketone bodies

196
Q

Under resting conditions the skeletal muscle uses ______ as a fuel source. When working it will ________

A

Fatty acids; break down own stores of glycogen to produce glucose-6-phosphate

197
Q

If the production of pyruvate exceeds the oxygen capacity of the muscle cell, then pyruvate is converted into ____

A

Lactate

198
Q

During fasting/starvation the liver will convert ______ to acetoacetate and other ketone bodies

A

FAtty acids

199
Q

GLUT 1

A

Red Blood Cells

200
Q

GLUT 2

A

Liver

201
Q

GLUT 3

A

Brain

202
Q

GLUT 4

A

Adipose and Muscle

203
Q

Insulin is an ____ hormone where glucagon is a ____ hormone

A

Anabolic; catabolic

204
Q

Insulins roles

A
  • Favors glycogen storage
  • Boosts protein synthesis
  • Promotes glycolysis
  • Increases conversion of carbohydrates to fatty acid
  • Promotes glucose uptake in muscle and adipose
205
Q

Insulin signals transcription of which enzymes

A

Glucokinase
PFK 1
Pyruvate kinase

Acetyl CoA Carboxykinase

206
Q

Glucagon roles

A

Promotes glycogen breakdown
Promotes gluconeogenesis
Stimulates fat breakdown

207
Q

Glucagon signalling causes a increase in cAMP levels
This results in the net ________ of
several key metabolic enzymes

A

Phosphorylation

208
Q

Roles of Cortisol

A
  • Promotes gluconeogenesis.
  • Mobilizes amino acids from extrahepatic tissues.
  • Inhibits glucose uptake in muscle and adipose tissue.
  • Stimulates fat breakdown - lipolysis.
209
Q

Which enzymes are induced by the signaling of cortisol

A

PEPCK
Fructose 1,6 biphosphate
Glucose 6 Phosphate
Hormone Sensitive Lipase

210
Q

What is one of the fastest enzymes known

A

Carbonic anhydrase

211
Q

What is enzyme specificity due to?

A

Precise interactions of substrate with enzyme due to the 3D structure of the enzyme

212
Q

6 Classes of Enzyme

A 
TILLOH:
Transferases
Isomerases
Ligases
Lyases
Oxioreductases
Hydrolases
213
Q

6 Classes of enzyme with examples

A

TILLOH AT AR GS F LD P
“At Arizona Georgia State Florida LondonDerry Pigs”

Alanine Transaminase
Alanine Racemase
Glutamine Synthetase
Fumarase
Lactate Dehydrogenase
Phosphatase
214
Q

An enzyme without its cofactor is a ?

A

Apoenzyme

215
Q

A completely catalytically active enzyme is called a…?

A

Holoenzyme

216
Q

Co enzymes

A

Small organic molecules derived from vitamins

217
Q

Co factors

A

Metals

218
Q

Tightly bound coenzymes are called _____ groups

A

Prosthetic

219
Q

Reaction takes place spontaneously only if delta G is _____ and ____

A

Negative; Exergonic

220
Q

Reaction cannot take place spontaneously if delta G is _____ and ____

A

Positive; Endergonic

221
Q

When is Vmax reached? What does it tell us?

A

When the enzyme is saturated with substrate; turnover rate of an enzyme

222
Q

Km is equal to

A

Substrate concentration at which the reaction velocity is half its maximal value

223
Q

A low km value indicates _____

A

Tightly bonded substrate

224
Q

3 main types of reversible inhibition

A

Competitive inhibition
Uncompetitive inhibition
Noncompletitive inhibition

225
Q

Competitive inhibitor

A
  • resembles the substate and binds only to the free enzyme active site
  • has no effect on Vmax but increases Km
226
Q

Uncompetitive inhibition

A
  • Binds only to the enzyme-substrate complex and not the free enzyme
  • Decreases vmax and decreases km
227
Q

Noncompetitive

A
  • can bind to both the free enzyme and the enzyme substrate complex
  • decreases vmax and does not change Km
228
Q

Irreversible enzyme inhibition

A

Form stable covalent bonds with the enzyme

BMS 102 (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions