Brainscape's Knowledge GenomeTM

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


See full index

BDS1 Semester 1 > Week 2: macromolecules - Carbohydrates + lipids (S&F) > Flashcards

Week 2: macromolecules - Carbohydrates + lipids (S&F) Flashcards

1
Q

what are the 4 types of carbohydrates?

A
  1. Monosaccharides
  2. Diasaccharides
  3. Oligosaccharides
  4. Polysaccharides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is a monosaccharide and what are they called when they have different number of carbons?

A
  • e.g. glucose and fructose
  • simple sugars
  • freely soluble in water and colourless
  • crystalline solids
  • contains different numebr of carbon atoms:
    1. trioses = 3 carbons
    2. tetrose = 4 carbons
    3. pentose = 5 carbons
    4. hexoses = 6 carbons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is a disaccharide?

A
  • 2 monochaccharide units joined by glycosidic linkages (covalent bonds).
  • e.g. sucrose (glucose + fructose), maltose (2x glucose)
  • alpha or beta form.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is a Oligosaccharide?

A
  • 3-10 monosaccharide units
  • usually covalently joined to a non-sugar molecule (lipid or protein) to form glycoconjugates.
  • e.g. glcoconnjugates = glycolipids and glycoproteins.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is a polysaccharide?

A
  • long chains of carbohydrate molecules, composed of 100-1000s monosaccharide units, joined by glycosidic linkages.
  • most carbohydrates in nature
  • high molecular weight.
  • e.g. starch (potatoes), cellulose (wood), glycogen (storage of glucose in liver/muscles)
  • can be branched or unbranched.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how are the 4 ways polysaccharides can differ?

A
  1. the recurring monosaccharides
  2. length of the chains
  3. type of glycosidic bonds linking the units
  4. degree of branching which determins the solubility of diff. polysaccharides.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the 2 types of polysaccharides

A
  1. Homopolysaccharides
    - contains only 1 type of monosaccharide units.
    - e.g. storage = glycogen and starch
    - e.g. structural = cellulose and chitin.
  2. Heteropolysaccharides
    - 2 or more types of monosaccharide units
    - involved in extracelllular support and protection
    - e.g. peptidoglycans (in bacteria walls), proteoglycans, hyaluronic acid.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is a glycosidic bond?

A
  • covalent bonds
  • joins monosaccharides to form poly- or di- saccharides.
  • during polysaccharide synthesis –> condensation reaction process where one enzym eists for each monosaccharide.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the 2 types of glycosidic bonds?

A

**1. Alpha **
- OH group of the first numerica carbon of the first monosaccharide is below the plane of the carbohydrate ring.

2. Beta
- Oh group of the 1st carbon of the 1dt monosaccharide is above the carbohydrate ring.

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

what is hyaluronic acid?

A
  • located in the epidermis
  • helps skin stretch and flex, reduces wrinkles and lines, helps wounds heal faster, reduce scarring.
  • have a high net-negative charge –> produces viscous, long, thin, molecules.
  • negative chanrges repel eachother –> pushes molecule out into a long polysaccharide chain.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is a proteoglycan

A

a hylauronic acid attached to extracellular protein/ carbohydrate molecule called aggrecans.
- e.g. central components of the ECM of cartilage and tendons.

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

why are polysaccharides (such as glycogen) relatively insoluble?

A
  • glycogen is a storage polymer - more compact due to higher degree of branching than starch
  • glycogen is insoluble in liver and muscles –> :. contribute less to osmotic strength of cytosol.
  • does not have free polar groups to H-bond with water –> water cannot surround the molecule :. relatively insoluble.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the biological advantage of glycogen for bacteria and mammal?

A
  • high dregree of branching –> allows for faster breakdown of polymers into monomers (monosaccharides) by having multiple sites for ezyme attachement
  • this produced glucose faster –> faster production of energy via storage.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how are glycosidic linkages notes - type of glycosidic bond and location.

A
  1. alpha or beta
  2. location (e.g. 1–> 4 or 1–6)
    - a (1–> 4) = alpha glycosidic bond joins the 1st carbon of one monosaccharide unit to the 4th one of the other monosaccharide unit.
    - a(1–>6) = alpha glycosidic bond between 1st and the 6th carbons. in glycogen, this occures every 8-12 glucose units while the rest is a(1–>4) which causes branching of molecules due to different orientation of the second monosaccharide.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how does structure of glycogen assist with storage and fight or flight response?

A
  • glucose is highly branched :. more opportunity for enxymes to bind and attack glycosidic linkages to break off glucose into blood stream
  • the glucose then undergoes aerobic respiration –> makes ATP –> used as energy in th body.
  • during fight or flight scenarios, there is a high requirement of energy (ATP) for muscles, therefore, due to the branching of glycogen, it can be broken down quicker and glucose be released into blood stream faster.

for storage:
- the a(1–>4) glycosidic linkages allow for a tightly coild helical structure –> molecule is relatively insoluble and does not draw in lots of water –> perfect for storing.

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

what is glycogenolysis

A

the process in which glycogen down via glycosidic linkages to glucose molecules which then ungergo aerobic respiration to create ATP.

17
Q

where is glycogen stored in

A

liver and skeletal muscle.

18
Q

what is peptidoglycans and what role does it play in bacteria?

A
  • made up of heteropolysaccharides of alternating B(1–>4) linked GAGs.
  • GAGs lay side by side in cell wall and cross link by short pepides ==> peptidoglycans.
  • serves a structural role in bacterial cell wall –> gives strength and counteracts the osmotic pressure of cytoplasm.
19
Q

what do lysozymes do to peptidoglycans?

A
  • lysozymes degrade peptidoglycans.
  • hydrolyses glycosidic bonds in the GAGs –> breaking down the peptidoglycan in cell wall structure.
    –> leads to rapid killing of gram-positive organisms.
20
Q

what is gram-negative and gram-positive bacteria?

A
  • gram-negative = This layer of peptidoglycan
  • gram-positive = Thick layer of peptidoglycan
21
Q

structure of proteoglycans

A
  • usually hyaluronic acid attached to extracellular protein/corbohydrate molecule.
  • long strands of hyaluronate to which core proteins or aggrecans are attached non-covalently.
  • core proteins have shorter GAGs covalently attached which are negatively charged :. repel eachother
  • very large molecule with upto 150 polysaccharide chains attached to core protein making up an aggrecan and more than 100 aggrecans attached to a hayularonate –> making a proteoglycan.
22
Q

role of proteoglycan on extracellular matrix

A
  • proteoglycans are hyaluronic acid usually attached to extracellular protein/carbohydrates (aggrecans)
  • form viscous solution –> lubricants in synovial fliud
  • central components of extracellular matrix of cartilage and tendon.
23
Q

what is a glycoprotein

A

oligosaccharides attached to proteins

24
Q

what are proteoglycans

A

hyularonic acid attached to extracellular protein/carbohydrate molecules called aggrecans.

25
Q

what are lipo-polysaccharides

A

important outer membrane components of gram-negative bacteria and a prime target of antibodies.
- lipid portion is toxic to humans and responsible for paritally lethal low BP

26
Q

what is a saturated fatty acid?

A
  • no double bonds between carbon molecules
  • straight carbon chain :. can stack closely.
  • derived from animals
  • generally considered harmful
  • solid at room temp
27
Q

what is an unsaturated fatty acid?

A
  • at least 1 double bond, kink in the structure
  • molecules cannot stack closely
  • derived from plants and marine animals
  • generally associated with health
28
Q

what are the 2 types of unsaturated fatty acids?

A

1. mono-unsaturated fatty acids
- one double bond

2. poly-unsaturated fatty acids
- more than 1 double bond
- e.g. omega-3 and -6

29
Q

what are Omega-3 and 6 fatty acids

A

Omega 3
- double bond at 3 carbons from the omega (last) carbon

omega-6:
- double bond at 6 carbons from the omega carbob

both cannot be synthesised in the body and must be via diet

30
Q

what is a triglyceride?

A
  • large ester molecule
  • 3 fatty acid molecules with a glycerol
  • react in a condensation reaction producing a water molecule in the process
31
Q

what is a sphingolipid?

A
  • class of membrane lipids
  • vital for structural and signalling molecules in organisms
  • 2 polar head groups, 2 non-polar tails –> :. amphipathic molecule due to presence of both domains.
  • core = long chain amino alcohol sphingosine - act similarly to glycerol
  • component of all membranes and abundant in myelin sheath.
32
Q

what is a phospholipid?

A
  • formation of lipid bilayer/ cell membrane.
  • hydrophobic, phosphate head
  • hydrophillic lipid tail - 2 fatty acids
    - one fatty acid = saturated (straight chain)
    - one fatty acid = unsaturated (kink in chain)
33
Q

what does the double bond (kink) in the carbon chain of a fatty acid do to its physical properties?

A
  • the kink = chain can’t be closely stacked together –> weak secondary properties which decreases melting point.
  • –> at room temp. unsaturated fatty acids = liquid
  • –> at room temp. saturated fatty acids = solid
34
Q

why does the structure of triglycerides allow for storage of fat in adipose tissue?

A

triglycerides contain 3 fatty acids attached to a glycerol molecule.
- the hydrocarbon fatty acids are dense with energy are they are convalently bonded. –> therefore, have high energy stores.
- they have low solubility in water –> hence, triglycerides can aggregate together without dissolving aqueous environment –> facilitating their storage as droplets in adipose cells.
- hydrolysis of the triglycerides to form fatty acids will be used during periods of energy deprivation

35
Q

what is amphipathic and give an example?

A
  • a molecule which contains both hydrophillic and hydrophobic parts.
  • example: phospholipid.
36
Q

3 types of membrane lipids

A

phospholipids, glycolipids and sphingolipids.

37
Q

how are lipids associated with blood groups?

A
  • glycolipids in the membrane of red blood cells determin the blood group.
38
Q

what role does cholesterol play in cell membrane?

A
  • maintians membrane fluidity
  • at high temp, acts to stabalise cell membrane and increase melting point
  • at low temp, cholesterol inserts into phospholipids and prevents them from interfering with eachother –> avoid aggregation.

BDS1 Semester 1 (18 decks)

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