Chapter 5 - An introduction to Carbohydrates Flashcards

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

what four types of macromolecules were crucial to the evolution of the cell?

A

proteins
carbohydrates
nucleic acids
lipids

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

of the five fundamental characteristics of life, which can proteins and nucleic acids carry out?

A

information
replication
evolution

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

which fundamental characteristic of life can carbohydrates carry out?

A

energy

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

what are the monomers of sugars/carbs?

A

monosaccharides (“one sugar”)

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

what do monosaccharides polymerize to form?

A

polymers - polysaccharides (“many sugars”)

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

what are small polymers of sugar called?

A

oligosaccharides (“few sugars”)

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

what is the molecular formula for most sugars/carbohydrates?

A

(CH2O)n (subscript n refers to the number of carbon hydrate groups)

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

what are some of the functions of carbohydrates?

A
  • raw material for synthesizing other molecules
  • providing structural support
  • indicating cell identity
  • storing chemical energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the two possible configuration of the carbonyl group in a sugar molecule? (two possible positions)

A

aldose - carbonyl group at the end of the carbon chain
forms an aldehyde

ketose - carbonyl group in the middle of the carbon chain
forms a ketone

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

triose

A

three carbon atoms present

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

pentose

A

five carbon atoms present (ribose)

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

hexose

A

six carbon atoms present (glucose and galactose)

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

what characteristics do the carbonyl group and the multiple hydroxyl groups bring to the sugar molecule?

A

-provides sugars with an array of reactive and hydrophilic functional groups

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

what are the 3 main ways that simple sugars differ from each other?

A
  • location of carbonyl group
  • number of carbon atoms present
  • spacial arrangement of their atoms (especially positions of hydroxyl (-OH) groups
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what structures do sugars tend to form in aqueous solutions?

A

ring structures

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

what is a complex carbohydrate?

A

polysaccharide (polymer of monosaccharide monomers)

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

disacharides

A

simplest polysaccharides

-consist of two monosaccharide monomers

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

glycosidic linkage

A

a covalent bond which links two hydroxyl groups through a condensation reaction
-bonds simple sugars and allows polymerization

19
Q

why can the location and shape of glycosidic bonds vary greatly?

A

because these linkages can form between any two hydroxyl groups

20
Q

how do plants store sugar?

A

starch

21
Q

what is starch comprised of?

A

-mix of branched amylopectin/unbranched amylose

22
Q

how do animals store sugar?

A

glycogen

23
Q

what is glycogen comprised of?

A

highly branched glucose polymer

24
Q

what is cellulose?

A

structural polymer of plants cell walls

25
Q

what is cellulose comprised of?

A

polymer of glucose monomers

26
Q

chitin

A

structural polymer of fungi cell walls, some algae, and animal cytoskeletons

27
Q

what is chitin comprised of?

A

N-acetylglucosamine (NAc) monomers

28
Q

peptidoglycan

A

provides support for bacterial cell walls

29
Q

what is peptidoglycan comprised of?

A

alternating monosaccharides

30
Q

which 3 carbohydrates provide structure?

A
  • cellulose
  • chitin
  • peptidoglycan
31
Q

did polysaccharides play any role in the origin of life?

A

probably not.

  • monosaccharide polymerization requires specialized enzymes
  • polysaccharides to not catalyze and known reactions
  • polysaccharide monomers cannot copt themselves because they don’t store that information
32
Q

what are glycoproteins made of?

A
  • proteins joined to carbohydrates by covalent bonds that contain sugar groups
  • they display info outside of the cell
33
Q

what is glycoprotein function? what do they do?

A
  • display information on the outer surface of the cell
  • key in cell to cell recognition and signaling
  • each cell has glycoproteins on its surface that identify the type/species of cell
34
Q

why is it possible for there to be so many different types of glycoproteins?

A
  • variety in monosaccharides and how they can be linked
  • makes it possible for a huge number of oligosaccharides to exist = many combinations of glycoprotein identities for each cell species
35
Q

in chemical evolution, how was energy harnessed and stored?

A

kinetic energy of sunlight/heat were converted into chemical energy and stored in the bonds of H2CO and HCN

36
Q

today, how is most energy (sugars) produced and stored?

A

photosynthesis!

-transforms energy of sunlight into chemical energy of C-N bonds in carbohydrates

37
Q

photosynthesis (know reactants/products)

A

CO2 + H2O + sunlight = (CH2O)n + O2

-plants harvest the kinetic energy of the sun and store it in the bonds of carbohydrates

38
Q

why do carbohydrates hold more free energy than CO2?

A

Carbohydrates: electrons in C-H and C-C bonds are shared more equally and less tightly. C-H bonds have high free energy

CO2: electrons in C-O bonds are held tightly

39
Q

phosphorylase (what is it/what does it do?)

A

enzyme that catalyzes hydrolysis of glycosidic linkages in glycogen

40
Q

why do most animal cells contain phosphorylase?

A

so they can readily break down glycogen and provide glucose

41
Q

amylase (what is it/what does it do?)

A

enzyme that catalyzes hydrolysis of starch

-plays a key role in carbohydrate digestion

42
Q

ATP (what is it/what does it do?)

A

adenosine triphosphate

  • produced by carbohydrate reactions
  • drive endergonic reactions/do work for the cell
43
Q

why are fatty acids even more energized than carbs?

A

carbs: C-H bonds hold high free energy

fatty acids: they have even more C-H bonds, so more energy!

44
Q

a-linkages vs. b-linkages (characteristics)

A
a linkages are readily hydrolyzed (store energy)
b linkages (structural) resist enzymatic degradation