Brainscape's Knowledge GenomeTM

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


See full index

NUTR 3210 > carbohydrates > Flashcards

carbohydrates Flashcards

1
Q

describe monosaccharides-

A
  • most common is glucose
  • naturally occurring
  • can’t be hydrolyzed into a smaller unit
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the most commonly found monosaccharide

A

glucose

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

when is a monosaccharide considered a reducing sugar

A
  • considered a reducing sugar when the anomeric carbon is free
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

describe disaccharides

A
  • most common is sucrose

- two monosaccharides joined by an acetyl bond (glycosidic)

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

what kind of bond joins monosaccharides together, forming polysaccharides?

A

the monosaccharides are joined by an acetyl bond- aka glycosidic bond

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

what is the ratio of H:O in all CHO

A

2:1

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

position of triode monosaccharides?

A

metabolism of glucose

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

position of pentose monosaccharides?

A

components of DNA and RNA

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

position of hexose monosaccharides

A

nutritionally the most important

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

what is a chiral carbon?

A

a carbon with four different components attached

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

what are the two types of chiral carbons?

A
  • enantiomers

- diastereomers

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

what are enantiomers

A

mirror images

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

what are diastereomers

A

not a mirror image

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

how do you determine a D vs an L sugar

A
  • determined by the -OH group on the highest chiral carbon
  • Oh on the right= D
  • OH on the left = L
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how do you determine the number of stereoisomers for a molecule?

A

stereoisomers= 2^n

n= # chiral carbons

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

are D or L sugars more nutritionally important?

A

D are nutritionally more important because digestive enzymes are stereospecific for D sugars

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

what are the basic rules for nomenclature in terms of converting towards fischer projection to Haworth model

A

LAB vs RBa
(left/above/beta)
(right/below/alpha)

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

describe sucrose

A
  • found in sugar cane and fruits
  • product of glucose + fructose
  • non-reducing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

describe lactose

A
  • found in milk
  • product of galactose + glucose
  • reducing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

describe maltose

A
  • found in beer and liquor
  • glucose + glucose
  • reducing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

describe polysaccharides

A
  • long strings or branches of monosaccharides (min 6) attached by glycosidic bonds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is the polysaccharide in plants

A

starch (amylose, amylopectin)

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

what is the polysaccharide in animal tissue

A

glycogen

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

what is the advantage for branched polysaccharides

A

this provides a larger number of ends from which to cleave glucose when energy is needed

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

describe cellulose

A
  • both a dietary fibre and functional fibre (naturally occurring but also added to foods for supplement)
  • poorly fermented by human gut bacteria
  • rich in bran, legumes, nuts, peas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

describe hemicellulose

A
  • a heteropolysaccharide that varied between plants

- mixture of alpha and beta glycosidic bolds

27
Q

describe pectin

A
  • both a dietary and functional fibre
  • part of the primary cell wall of plants
  • highly fermented by gut bacteria (therefore a good bulking agent in animal feeds)
28
Q

describe resistant starch

A
  • typically found in plant cell walls
  • resistant to amylase activity
  • conveys some advantaged to both soluble and insoluble fibres
29
Q

what are the health benefits of fibre

A
  • maintains function and health of the gut
  • insoluble fibres reduce constipation
  • soluble fibres increase satiety (the feeling of being full)
30
Q

describe the correlation between soluble fibre and disease risk

A
  • decrease cardiovascular disease risk by lowering blood cholesterol
31
Q

describe carb digestion within the mouth

A
  • saliva breaks down alpha-1,4- glycosidic bonds

- produced a few monosaccharides (cellulose and lactose are resistant)

32
Q

describe carb digestion within the stomach

A
  • alpha amylase (in saliva) digestion continues until pH drops- then enzyme is deactivated
  • CHO will not consist of small polysaccharides and maltose
33
Q

describe carb digestion within the small intestine

A
  • pancreatic alpha-amylase is active at neutral pH

- alpha 1,6 binds are resistant and eventually produce is-maltose

34
Q

describe people wit more copies of the AMY1 gene

A

people with more copies of the AMY1 gene gave overall more amylase activity in saliva

35
Q

describe lactose intolerance

A
  • missing lactase enzyme
  • cant convert lactose to glucose and galactose
  • rather, once lactose meets the bacteria within the large intestine, fermentation occurs (which produces gasses, organic acids, and other osmotically active molecules)
36
Q

how do genetics play a factor in lactose intolerance

A
  • ethnicity (asian vs northern europeans)

- variance in the LCT gene (which encodes the lactase enzyme) contributes to an intolerance

37
Q

what are enterocytes

A

polarized cells (they have an up and a down)

38
Q

describe monosaccharide absorption

A
  • nearly all monosaccharides are taken up by enterocytes
  • once taken in, small amounts of glucose leak back out into human, and small amounts diffuse into blood through the base lateral membrane, all while the majority of glucose is transported into blood through GLUTZ
  • transport of glucose and galactose from lumen into blood is dependent on basolateral Na-K ATPase activity
  • fructose is taken up by facilitated transport
  • glucose, galactose, and fructose all enter blood via basolateral GLUT2
39
Q

what is SGLT1

A

sodium glucose transport

- transports glocose and galactose

40
Q

on the apical side of the enterocyte, what occurs

A

uptake of monosaccharides

using the SGLT1 transport

41
Q

on the basolateral side of the enterocyte, what occurs?

A

absorption

using GLUT2

42
Q

what are the functions of carbs within the body?

A
  • primary source of energy
  • they “spare” protein
  • prevent ketosis (and therefore acidic blood)
  • primary source fo energy for therein and red blood cells
43
Q

what I ketosis

A
  • when carbs are limited, fats are broken down for energy

- leads to the production of ketone bodies- causing the body’s pH to become slightly acidic

44
Q

how do carbs spare protein

A
  • prevents the breakdown of protein for energy
  • allows protein to concentrate on building, repairing, and maintaining body tissue

(if carbs are low, body will breakdown protein to keep the Krebs cycle going)

45
Q

why are red blood cells dependent on glucose

A

they dont have mitochondria- and since things cant be oxidized without mitochondria- no energy will be formed

46
Q

what are the three fates of glucose in cells

A
  1. enters glycigenisis for energy storage
  2. enters glycolysis for energy production
  3. enters hexose monophosphate shunt to generate precursors for biogenesis
47
Q

what is glycogenin

A

an enzyme that serves as a scaffold on which to attach glucose molecules to build glycogen

48
Q

how does glycogenin work?

A
  • initially attaches glucose molecules to itself before glycogen synthase takes over and adds glucose to the growing glycogen store
49
Q

how many glucose molecules can be contained in a single glycogen store

A

30 000 + glucose molecules can be contained in a single glycogen store

50
Q

where is energy produced in the cell?

A
  • substrate-level phosphorylation (Krebs cycle) occurs in the mitochondria
  • oxidative phosphorylation (glycolysis) occurs in the cytoplasm
51
Q

what is glycolysis

A

turning glucose into pyruvate

52
Q

what is the first committed step in glycolysis

A

phosphofructokinase

53
Q

what is the net energy yield from on glucose that undergoes glycolysis

A

2 NADH + 2 ATP

equivalent to ~8 ATP

54
Q

describe lactic acid production

A
  • occurs in muscle during prolonged exercise and in RBC
  • pyruvate is converted into lactic acid in the cell’s cytosol
  • regenerates NAD+, which allows glycolysis to continue
  • a net of 2 ATP is produced when glucose is converted to lactic acid
55
Q

describe how ethanol is produced

A

(doesn’t happen in body)

  • yeast breaks down pyruvate into CO2 and ethanol
  • regenerated NAD+, which allows glucose to continue being broken down in glycolysis
56
Q

when does the Cori Cycle occur

A

the cori cycle occurs in times where oxygen is unavailable in the muscle- which leads to the production of lactate

57
Q

describe what happens in the Cori Cycle

A
  • used when oxygen is unavailable
  • lactate is transported back to the liver- where gluconeogenisis allows for the conversion of pyruvate back to glucose
  • for two molecules of lactate to form glucose, the cell consumes 6 ATP molecules
58
Q

how much ATP does it take to convert 2 molecules of lactate

A

it takes 6 ATP to convert 2 lactate molecules

59
Q

what is the function of the hexose monophosphate shunt

A

produces important molecules (ie- NADPH, ribose sugars)- that all other cells will use

60
Q

what is pyruvate dehydrogenase?

A

the “gatekeeper” to the Krebs cycle

61
Q

describe the Krebs cycle

A
  • over 90% of the energy in food is released in this process
  • a common and final catabolic pathway for products of protein, lipid, and carbs
  • takes place in mitochondrial matriculates
62
Q

how much energy do you get from 1 molecule of glucose

A

38 ATP

63
Q

describe gluconeogenisis

A
  • pathway that is active when glucose is needed in the body
  • very active in liver (but can also happen in the kidney during starvation)
  • muscle and adipose tissue lack enzymes for gluconeogenisis
  • high physical activity produced muscle lactate- which travels to liver tin the cori cycle

NUTR 3210 (6 decks)

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