Intro to Metabolism

Question 1

What is the difference between catabolism and anabolism?

Answer 1

catabolism: utilization of compounds for the generation of energy
anabolism: utilization of energy to produce compounds

Question 2

What do fats, polysaccharides, and proteins get broken down into during energy production?

Answer 2

fats: fatty acids and glycerol
polysaccharides: glucose and other sugars
proteins: AAs

Question 3

____ is an important intermediate in several pathways

Answer 3

acetyl-CoA

Question 4

Define glycogenesis and glycogenolysis.

Answer 4

glycogenesis: synthesis of glycogen
glycogenolysis: breakdown of glycogen

Question 5

The pentose phosphate pathway generates what?

Answer 5

NADPH and 5 carbon sugars (ribose) for nucleotides

Question 6

What are the starting and ending products of glycolysis

Answer 6

glucose -> pyruvate

Question 7

What are some important side products from glycolysis in some tissues?

Answer 7

glycerol-3-phosphate

2,3-bisphophoglycerate

Question 8

What is gluconeogensis and where does it take place?

Answer 8

synthesis of glucose from pyruvate; restricted to liver and kidney

Question 9

____ is also the source for carbohydrates in glycoproteins and proteoglycans

Answer 9

glucose

Question 10

Acetyl-CoA from carbohydrate and/or protein can be utilized to make ___

Answer 10

fat

Question 11

Acetyl-CoA is a substrate for what? (4)

Answer 11

1. TCA cycle
2. lipogenesis
3. cholesterol synthesis
4. ketone bodies

Question 12

____ ____ are also required for complex lipids, components of membranes

Answer 12

fatty acids

Question 13

Some AAs can produce acetyl-CoA, some AAs can produce carbohydrate intermediates. In both cases, what happens to the AA?

Answer 13

1. AA is eliminated as urea

2. AA is re-utilized to form another AA

Question 14

AAs are the source of nearly all the ___ in compounds making up an organism

Answer 14

nitrogen

Question 15

More than one pathway may be required for some special compounds. Describe what Phospholipids and Nucleotides require.

Answer 15

Phospholipids: require contribution from lipids, carbohydrates, and AAs

Nucleotides: require contribution form AAs and carbohydrates

Question 16

Gluconeogeneis only occurs where?

Answer 16

liver and part of kidney

Question 17

Red blood cells contain no ____, and cannot utilize ___ ___ metabolism

Answer 17

mitochondria; aerobic carbohydrate

Question 18

Organs participate in specialized pathways associated with their function. ___ hormones are produced in endocrine glands

Answer 18

steroid

Question 19

Some storage forms of molecules are restricted to certain organs. Where are glycogen and triacylglycerols stored?

Answer 19

glycogen: only in muscle and liver
triacylglycerols: only in adipose tissue

Question 20

Pathways may be found only in certain sub cellular locations. Fatty acid oxidation and fatty acid synthesis both occur where?

Answer 20

liver

Question 21

Fatty acid oxidation occurs only inside _____, while fatty acid synthesis occurs only in ____

Answer 21

mitochondria; cytosol

note: this arrangement prevents “futile cycling”

Question 22

Control of a pathway is through control of ___ activity

Answer 22

enzyme

Question 23

A key regulated enzyme of glycolysis is affected ____ by a product of the pathway. This is an example of what?

Answer 23

allosterically; example of feedback inhibition

Question 24

True or false? an enzyme responds the same way to the same hormone in different tissues

Answer 24

false; responds differently

Question 25

``` For each of the following components, give their associated amount of calories/gram: carbohydrate protein ethanol fat ```

Answer 25

carbohydrate: 4 protein: 4 ethanol: 7 fat: 9

Question 26

There are no essential carbohydrates since there are biochemical mechanisms to synthesize required carbohydrates from non-carbohydrate molecules

Answer 26

true

Question 27

The "typical" western diet consists of about half the calories from _____

Answer 27

carbohydrates

Question 28

In regards to fiber, cellulose and himicelluloses ____ stool bulk and ____ transit time

Answer 28

increase; decrease

Question 29

In regards to fiber, lignins ____ stool bulk and bind what two things

Answer 29

increase; bind cholesterol and carcinogens

Question 30

In regards to fiber, pectin and gums decrease rate what 3 things?

Answer 30

decrease rate of gastric emptying decrease rate of carbohydrate absorption decrease serum cholesterol

Question 31

What does the glycemic index show?

Answer 31

the effect of a standard amount of carbohydrate on blood glucose concentration compared to the effect of a standard amount of glucose

Question 32

A higher glycemic index would be expected to ____ blood glucose faster and lead to a greater release of ____

Answer 32

raise; insulin

Question 33

What is the recommended protein intake?

Answer 33

0.8 g/kg body wt/day

Question 34

Protein intake needs to be increased during growth and illness. True or false?

Answer 34

true

Question 35

What are the essential AAs?

Answer 35

Threonine, Tryptophan, Valine, Arginine, Histidine, Lysine, Phenylalanine, Leucine, Isoleucine, Methionine mnemonic: These Ten Valuable Amino-acids Have Long Preserved Life In Man

Question 36

____ is sometimes considered essential for growing children

Answer 36

arginine

Question 37

Positive nitrogen balance: more nitrogen ingested than excreted occurs during what two periods?

Answer 37

growth; convalescence

Question 38

Negative nitrogen balance: more nitrogen is excreted than ingested occurs when?

Answer 38

starvation; diseases; severe burns

Question 39

Fats require essential fatty acids. What are these two essential fatty acids?

Answer 39

Linoleic acid (18:2), Linolenic acid (18:3)

Question 40

What is the recommended intake of fat in a balanced diet? give in percentage of total calories

Answer 40

20-35%

Question 41

In regards to under-nutrition, describe Marasmus.

Answer 41

1. Occurs in both adults and children 2. extreme emanation from prolonged negative energy balance 3. loss of protein from muscle, heart, liver, and kidneys

Question 42

In regards to under-nutrition, describe kwasiorkor

Answer 42

1. affects undernourished children primarily in the developing world 2. thought to be due to a diet adequate in calories but sufficient in protein 3. poor growth, low plasma protein and AA levels, muscle wasting, edema, fatty liver, diarrhea, increased susceptibility to infection