Brainscape's Knowledge GenomeTM

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


See full index

Biology > Carbohydrates and Lipids A1 > Flashcards

Carbohydrates and Lipids A1 Flashcards

1
Q

Define the term monomer with examples.

A
  1. small identical or similar molecules
  2. can be joined together to make larger molecules called polymers
  3. eg. monosaccharides (alpha and beta glucose), amino acids, nucleotides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define the word polymer.

A

Large molecules made from joining many similar or identical monomers together.

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

Describe hydrolysis and condensation reactions.

A
  1. hydrolysis reactions involve adding one molecule of water to break the bond between two monomers
  2. condensation reactions join two monomer units together with the removal of one water molecule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Give the elements found in carbohydrates.

A

Carbon (C)
Hydrogen (H)
Oxygen (O)

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

Give the molecular formula for glucose.

A

C6-H12-O6

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

Be able to draw the structure of alpha and beta glucose.

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

Glucose + glucose =

A

maltose

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

Glucose + galactose =

A

lactose

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

Glucose + fructose =

A

sucrose

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

What bond is formed in the reaction of two monosaccharides?

A

glycosidic bond

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

What is the molecular formula of disaccharides?

A

C12 H22 O11 (due to the loss of 1 water molecule)

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

What is a polysaccharide?

A
  1. a type of polymer formed by joining many monosaccharides together
  2. storage - starch (plants) + glycogen (human)
  3. structural - cellulose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the structure of amylose (starch)
(5)

A
  1. long and straight chains of alpha glucose which coil into a helix
  2. carbon 1:4 glycosidic bonds
  3. compact structure for storage
  4. insoluble so does not affect water potential
  5. does not diffuse out of cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the structure of amylopectin (starch)
(5)

A
  1. branched chain of alpha glucose molecules
  2. carbon 1:4 and 1:6 glycosidic bonds
  3. provides large SA for rapid hydrolysis by enzymes
  4. insoluble so does not affect water potential
  5. does not diffuse out of cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does glycogen differ to starch and why?

A

similar however:
1. shorter chains - more readily hydrolysed into glucose (quicker)
2. more branched
3. large SA
4. stored in muscles and liver
5. like starch glycogen is insoluble so does not affect water potential or diffuse out of cells.

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

A starch molecule has a spiral shape.
Explain why this shape is important to its functions in cells.

A

compact/occupies small space/tightly packed

17
Q

Explain one way in which starch molecules are adapted for their functions in plant cells.

A
  1. insoluble
  2. don’t affect water potential
    or
  3. helical
  4. compact
    or
  5. large molecule
  6. cannot leave cell
18
Q

Give the structure of alpha glucose and two examples.

A
  1. alpha helix
  2. starch and glycogen
19
Q

Give the structure of beta glucose and an example.

A
  1. beta pleated sheets
  2. cellulose
20
Q

Give the structure of cellulose.

A
  1. beta glucose joined together through condensation reactions to form long straight chains
  2. every other glucose molecule rotates 180 degrees to allow OH groups on carbon 1 and 4 to be adjacent to each other to form a glycosidic bond.
21
Q

The structure of cellulose is related to its role in plant cell walls.
Explain how.

A
  1. long/straight/unbranched chains of glucose
  2. joined by hydrogen bonds
  3. form micro/macrofibrils
  4. provides rigidity/strength/support
22
Q

Hydrogen bonds are important in cellulose molecules. Explain why.

A
  1. holds chains/cellulose molecules together/forms crosslinks between chains/cellulose molecules/forms microfibrils
  2. providing strength/rigidity to cellulose/cell wall
  3. hydrogen bounds strong in large numbers
23
Q

What are the three tests for carbohydrates?
Give the names of the carbohydrates being tested.

A
  1. Benedict’s test for reducing sugars (alpha glucose, galactose, lactose, maltose, fructose)
  2. Benedict’s test for non-reducing sugar (sucrose)
  3. iodine test (starch)
24
Q

Describe how a student would show that reducing sugars were present in a solution.
(3)

A
  1. add equal volumes of Benedict’s solution
  2. heat to 95 degrees celsius
  3. red/orange/yellow/green precipitate (shows reducing sugar is present)
25
Q

Describe how a student would show that a non-reducing sugar is present in a solution.

A
  1. add dilute hydrochloric acid (HCI) to sugar solution (to hydrolyse into monomer units)
  2. boil sugar solution
  3. add sodium hydrogen carbonate (NaHCO3) to neutralise
  4. add equal volume of Benedict’s solution to the sugar solution
  5. heat to 95 degrees celsius
  6. red/orange/yellow/green precipitate (shows reducing sugar present)
26
Q

Describe how you would test a sample of food for the presence of starch.

A
  1. add iodine solution to the food sample
  2. blue/black/purple indicates starch is present
27
Q

Benedict’s test is only a semi-qualitative test for sugars. How would you test for an unknown concentration of reducing sugars?

A

use a calibration curve

28
Q

Describe how you would produce a calibration curve and use it to obtain results.

A
  1. make up several known concentrations of maltose/glucose/lactose/galactose/fructose.
  2. carry out the Benedict’s test on each sample
  3. use a colorimeter to measure the colour of each solution and plot a calibration curve
  4. find the concentration of the unknown sample reading off the calibration curve
29
Q

Name the two types of lipid structures.

A
  1. triglycerides (commonly found in food)
  2. phospholipids (helps form cell membrane of a cell)
30
Q

How are triglycerides formed?

A
  1. made from one glycerol head (molecule)
  2. linked to three fatty acid tails
  3. joined together by a condensation reaction
  4. to form ester bonds
31
Q

How many water molecules does the condensation reaction of a triglyceride form and where do the ester bonds form?

A
  1. 3 condensation reactions so 3 water molecules
  2. ester bonds form at the carboxylic acid group
32
Q

Name and explain two different types of fatty acids.

A
  1. saturated fatty acid: single covalent bonds between carbons in the hydrocarbon chain
  2. unsaturated fatty acids: double bonds between carbons in hydrocarbon chain
33
Q

Describe how to carry out the emulsion test for lipids.

A
  1. place small amount of sample in test tube with 2cm³ of ethanol
  2. the mixture is shaken so that the fat dissolves
  3. water is then added drop by drop and shaken again
  4. a white and cloudy emulsion layer of fat droplets should be visible if fat is present
34
Q

The concentration of glucose in blood rises slower if the carbohydrate is starch rather than sucrose.
Explain why.

A
  1. starch gets digested to maltose first and then into glucose as its a polysaccharide
  2. sucrose can be digested into glucose straight away as its a disaccharide
35
Q

What are phospholipids made up of and what are their charges?

A
  1. a glycerol head
  2. two fatty acid tails (no charge - non-polar)
  3. phosphate group (negative charge - polar)
36
Q

How do phospholipids form a bilayer in the cell membrane?

A
  1. the phospho-glycerol head is hydrophilic (attracts water-soluble)
  2. the fatty acid tails are hydrophobic (repel water - not soluble)
  3. the hydrophobic fatty acid tails are arranged in the middle away from the water
  4. the hydrophilic heads are arranged on the outside in contact with the water
  5. this allows the phospholipids to form a bilayer in water
37
Q

What is the structural formula of a glycerol?

A

C3-O8-H3

38
Q

What’s the general formula of a fatty acid?

A

CH3-nCOOH

39
Q

Describe how the structure of a phospholipid is different to a triglyceride.

A
  1. fatty acid removed
  2. replaced with a phosphate group

Biology (27 decks)

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