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Flashcards in Intro to Metabolism Deck (42):
1

What is the difference between catabolism and anabolism?

catabolism: utilization of compounds for the generation of energy

anabolism: utilization of energy to produce compounds

2

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

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

3

____ is an important intermediate in several pathways

acetyl-CoA

4

Define glycogenesis and glycogenolysis.

glycogenesis: synthesis of glycogen
glycogenolysis: breakdown of glycogen

5

The pentose phosphate pathway generates what?

NADPH and 5 carbon sugars (ribose) for nucleotides

6

What are the starting and ending products of glycolysis

glucose -> pyruvate

7

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

glycerol-3-phosphate
2,3-bisphophoglycerate

8

What is gluconeogensis and where does it take place?

synthesis of glucose from pyruvate; restricted to liver and kidney

9

____ is also the source for carbohydrates in glycoproteins and proteoglycans

glucose

10

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

fat

11

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

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

12

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

fatty acids

13

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

1. AA is eliminated as urea
2. AA is re-utilized to form another AA

14

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

nitrogen

15

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

Phospholipids: require contribution from lipids, carbohydrates, and AAs

Nucleotides: require contribution form AAs and carbohydrates

16

Gluconeogeneis only occurs where?

liver and part of kidney

17

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

mitochondria; aerobic carbohydrate

18

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

steroid

19

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

glycogen: only in muscle and liver

triacylglycerols: only in adipose tissue

20

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

liver

21

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

mitochondria; cytosol

note: this arrangement prevents "futile cycling"

22

Control of a pathway is through control of ___ activity

enzyme

23

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

allosterically; example of feedback inhibition

24

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

false; responds differently

25

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

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

26

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

true

27

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

carbohydrates

28

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

increase; decrease

29

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

increase; bind cholesterol and carcinogens

30

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

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

31

What does the glycemic index show?

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

32

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

raise; insulin

33

What is the recommended protein intake?

0.8 g/kg body wt/day

34

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

true

35

What are the essential AAs?

Threonine, Tryptophan, Valine, Arginine, Histidine, Lysine, Phenylalanine, Leucine, Isoleucine, Methionine


mnemonic: These Ten Valuable Amino-acids Have Long Preserved Life In Man

36

____ is sometimes considered essential for growing children

arginine

37

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

growth; convalescence

38

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

starvation; diseases; severe burns

39

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

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

40

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

20-35%

41

In regards to under-nutrition, describe Marasmus.

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

42

In regards to under-nutrition, describe kwasiorkor

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