Brainscape's Knowledge GenomeTM

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


See full index

Biochemistry, genetics, and metabolism > intro to carbs > Flashcards

intro to carbs Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What is the most abundant molecule in nature?

A

carbohydrates

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

function of carbs in humans

A
  • significant fraction of dietary calories
  • major energy source
  • storage form of energy (glycogen)
  • cell membrane components that mediate some forms of intercellular communication and retain water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

structural component of many organisms

A
  • cell walls of bacteria
  • exoskeleton of insects (chitin)
  • fibrous cellulose of plant cell wall (indigestible)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

stoichiometric formula

A

(CH2O)n

consists of carbon and water in ratio of C:H:O= 1:2:1

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

monosaccharides

A
  • 1 unit
  • simple sugars
  • glucose and fructose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

disaccharides

A

-2 monosaccharide units

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

oligosaccharides

A

3-10 monosaccharide units

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

polysaccharides

A

more than 10 monosaccharide units

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

monosaccharide classification

A
  1. according to the number of carbons they contain

2. according to the type of there most oxidized functional group

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

isomers

A

compounds that have the same chemical formula but different structures

gluctose, fructose, mannose, and galactose are all structural isomers

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

epimers

A

compounds that differ in the configuration around only one specific carbon atom

glucose and galactose are C-4 epimers
glucose and mannose are C-2

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

enantiomers

A

pairs of structures that are mirror image to each other

D-glucose and L-glucose

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

D-glucose

A

found in nature

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

L-glucose

A

cannot be metabolized

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

monosaccharides: cyclization

A

> 99% of monosaccharides with 5 or more carbons exist as a ring, in which the aldehyde or kept group has reacted with an alcohol group of the same sugar

creates an anemic carbon (isomer) that can exist in either alpha or beta form

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

pyranose

A

6 membered ring with 5 carbons and one oxygen

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

Furanose

A

5 membered ring with 4 carbons and one oxygen

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

enzyme specificity of anomeric monosaccharides

A

they are specific to one of the anemic forms

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

Glycosidic bonds

A

bonds that link sugars

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

Beta gycosidic

A

beta(1-4)

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

alpha glycosidic

A

alpha(1-4)

alpha (1-6)

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

lactose

A

glucose + galactose

Beta (1-4)

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

Sucrose

A

glucose + fructose

alpha (1-2)

24
Q

Maltose

A

glucose + glucose

alpha (1-4)

25
Q

When can the ring on a cyclic mono-disaccharide open?

A

if the OH group on the anemic carbon of a cyclized sugar is NOT linked to another compound by a glycosidic bond

26
Q

reducing agent

A

the sugar can act as a reducing agent once the ring opens

27
Q

What can be a reducing sugar?

A

all monosaccharides but not all disaccharides

28
Q

positive urine test for reducing sugars

A

indicative of underlying pathology

29
Q

glycogen

A

highly branched polymer of glucose, alpha 1-4 and alpha 1-6 linkages
major energy storage in animal (liver and muscle cells)

30
Q

amylose

A

polymer of glucose in plants

unbranched; alpha 1-4 glycosidic linkages

31
Q

Amylopectin

A

polymer of glucose in plants
branched; alpha 1-4 and alpha 1-6 glycosidic linkages
a little less branched than glycogen

32
Q

cellulose

A

unbranched glucose polymer in plants
beta 1-4 glycosidic linkages
humans can’t digest

33
Q

complex carbs

A

carbs attached to non-carb structures such as

  • purines and pyramidines
  • aromatic rings (steroids)
  • proteins (glycoproteins)
  • lipids (glycolipids)
34
Q

types of bonds by which a sugar may be attached to a non-carb group

A
  • NH2 group = N-glycosidic link (N-linked)

- OH group = O-glycosidic link (O-linked)

35
Q

Where do carbs get digested?

A
  • mouth
  • intestinal lumen
  • mucosal lining of the upper jejunum
36
Q

What digestive enzymes break down carbs?

A

glycoside hydrolases (glycosidases), use a molecule of water

37
Q

Mouth enzymes

A

salivary alpha-amylase

38
Q

intestinal lumen enzymes

A

pancreatic alpha-amylase

39
Q

enzyme of the mucosal lining of the upper jejunum

A

isomaltase, galactosidase, trehalase

40
Q

what two enzymes act the same but are secreted from different tissues?

A

salivary alpha-amylase and pancreatic alpha-amylase

41
Q

role of salivary alpha amylase

A

breaks large insoluble carbs into smaller soluble ones

42
Q

specificity of salivary alpha amylase

A

hydrolysis of alpha 1-4 bonds ONLY

43
Q

substrates of salivary alpha amylase

A

any carb with alpha 1-4 bonds (starch, glycogen, maltose)

44
Q

salivary alpha amylase products

A

short branched and unbranched oligosaccharides (dextrins)

45
Q

salivary alpha amylase pH optimum

A
  1. 0

- inactivated by the acidic pH in stomach within 20 minutes

46
Q

pancreatic alpha amylase role

A

continues to break down carb molecules into smaller soluble ones

47
Q

pancreatic alpha amylase specificity

A

hydrolysis of alpha 1-4 bonds ONLY

48
Q

pancreatic alpha amylase substrates

A

any carb with alpha 1-4 bonds (starch, glycogen, maltose, and smaller dextrin)

49
Q

pancreatic alpha amylase product

A

shorter branched and unbranched oligosaccharides (dextrin) and disaccharides

50
Q

pancreatic alpha amylase pH optimum

A

7.0

51
Q

pancreatic alpha amylase and pathology

A

plasma levels of either pancreatic amylase or total amylase are used as a diagnostic marker for pancreatitis, should not be found in plasma

52
Q

final digestions in the mucosal cells

A

all enzymes are transmembrane proteins of the brush border on luminal surface of the intestinal mucosal cells

53
Q

sucrase/isomaltase (SI)

A

1 protein-2 subunits with enzymatic activities

  • cleaves alpha 1-2 bonds in sucrose
  • alpha 1-6 bonds (branches) in isolates
54
Q

maltase-glucoamylase (MGA)

A

1 protein-2 enzymatic activities

  • cleaves alpha 1-4 bonds in maltose/maltotriose (maltase activity)
  • alpha 1-4 bonds in dextrins (glucoamylase)
55
Q

lactase

A

beta 1-4 bonds in lactose (milk sugar)

high expression in infants and gradual decrease with age

56
Q

trehalase

A

alpha 1-1 bonds in therapies (mushrooms and fungi)

57
Q

What kind of sugars get absorbed?

A

ONLY MONOSACCHARIDES. in the upper jejunum and duodenum

Biochemistry, genetics, and metabolism (11 decks)

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