Brainscape's Knowledge GenomeTM

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


See full index

Biology - Unit 1-4 > 1. Lipids > Flashcards

1. Lipids Flashcards

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

Which 3 elements do lipids contain?

A

Carbon

Hydrogen

Oxygen

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

Which part of a phospholipid is hydrophilic?

A

The phosphate ‘head’

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

Identify the molecule

A

Polyunsaturatedfatty acid

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

Why are triglycerides called triglycerides?

A

They contain 1 glycerol molecule (glyceride) and 3 fatty acids (tri)

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

What does hydrophobic mean?

A

water hating

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

How does the structure of triglycerides relate to their properties?

A
  • High ratio of carbon-hydrogen bonds make them an excellent energy source
  • Low mass to energy ratio- animals don’t have to carry a heavy energy store around.
  • Non-polar molecules are insoluble in water so they do not affect osmosis in cells.
  • High ratio of hydrogen to oxygen atoms so water released when trigylcerides are oxidised. Good for animals in deserts.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Identify the molecule

A

Monounsaturated fatty acid

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

What decides the properties of different fats and oils?

A

Variations in their fatty acid chains

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

Identify the molecule

A

Phosphate molecule

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

What state do monounsaturated and polyunsaturated fats take at room temperature?

A

Liquid - they are oils.

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

What type of reaction takes place when a fatty acid molecule is removed from a glycerol molecule?

A

Hydrolysis

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

What is mean by a saturated fatty acid?

A

A fatty acid that contains no double bonds between the carbon atoms

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

What state do saturated lipids take at room temperature?

A

Solid - they are fats

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

Identify the molecule

A

Glycerol

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

Phospholipids are p___________ molecules

A

polar

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

What does the following describe:

  • Add 2cm3 of food and add to a test tube.
  • Add 5 cm3 of ethanol
  • Shake the tube thoroughly to dissolve any lipid.
  • Add 5cm3 of water and shake gently
  • A cloudy-white colour indicates a positive result.
A

The emulsion test for lipids

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

What is meant by a polyunsaturated fatty acid?

A

A fatty acid that contains more than 1 double bond between its carbon atoms.

18
Q

What does hydrophilic mean?

A

attracted to water

19
Q

What type of bond forms between glycerol and fatty acid molecules?

A

Ester bond

20
Q

Identify the molecule

A

Triglyceride

21
Q

Identify the molecule

A

Saturatedfatty acid

22
Q

What type of reaction takes place when a glycerol molecule joins with a fatty acid molecule?

A

Condensation reaction

23
Q

Describe how you would carry out an emulsion test for lipids

A

The emulsion test for lipids:

  • Add 2cm3 of food and add to a test tube.
  • Add 5 cm3 of ethanol
  • Shake the tube thoroughly to dissolve any lipid.
  • Add 5cm3 of water and shake gently
  • A cloudy-white colour indicates a positive result.
24
Q

Which part of a phospholipid is hydrophobic?

A

The fatty acid ‘tails’

25
Q

List the roles of lipids in living organisms.

A
  • Cell membranes
  • Energy store
  • Waterproofing
  • Heat insulation
  • Electrical insulation
  • Protection of organs e.g. kidneys
26
Q

What is meant by a monounsaturated fatty acid?

A

A fatty acid that contains 1 double bond between 1 pair of its carbon atoms.

27
Q

Describe the structure of a phospholipid

A

1 glycerol molecule attached to

2 fatty acid molecules and

1 phosphate molecule

28
Q

How does the structure of phospholipids relate to their properties?

A
  • Polar molecules - meaning that they can form a barrier (cell membrane) between water inside and outside a cell.
  • The phospholipid can form glycolipids by combining with carbohydrates. These are important in cell recognition.
29
Q

Name the 2 main groups of lipid

A

Triglycerides (fats and oils)

Phospholipids

30
Q

What happens when a phospholipid is placed in water?

A

The hydrophilic head positions itself towards water.

The hydrophobic tail positions itself away from water

31
Q

Identify the molecule

A

Phospholipid

32
Q

List the characteristics shared by all lipids

A
  • They contain: Carbon, Hydrogen and Oxygen
  • Lower proportion of oxygen to carbon and hydrogen than carbohydrates.
  • Insoluble in water
  • Soluble in organic solvents e.g. alcohols
33
Q

how do you test for lipids?

A

dissolve in alcohol, then

add water then

white emulsion shows presence of lipid

34
Q

name the bond between the glycerol and the fatty acid chains in a lipid molecule

A

ester

35
Q

How can you tell the difference between a fatty acid that is saturated and how which is not?

A

saturated FA have no double bonds between carbon atoms

36
Q

what is the difference between a triglyceride and a phospholipid?

A

in a phospholipid, one FA is replaced with a phosphate

37
Q

name the reaction to breakdown phospholipids to release the phosphate

A

hydrolysis

38
Q

name the element found in all amino acids but not in triglycerides?

A

Nitrogen

39
Q

Compare and contrast structure of triglycerides and phospholipids

A

Both have ester bond

both contain glycerol

fatty acids on both can be saturated or unsaturated

Both contain C, H, O but phospholipids have also P

Triglycerides have 3 FA, Phospholipds have 2 FA and 1 phosphate group

40
Q

Compare and contrast the structure and properties of triglycerides and phospholipids.

A
  1. Both contain ester bonds (between glycerol and fatty acid); All statements must be clearly comparative or linked by the candidate, not inferred from separate statements. Accept mark points shown on adjacent annotated diagrams.2. Both contain glycerol;3. Fatty acids on both may be saturated or unsaturated;4. Both are insoluble in water;5. Both contain C, H and O but phospholipids also contain P; Must relate to element.6. Triglyceride has three fatty acids and phospholipid has two fatty acids plusphosphate group;7. Triglycerides are hydrophobic/non-polar and phospholipids have hydrophilic and hydrophobic region;Accept ‘non-polar’ for hydrophobic and ‘polar’ for hydrophilic.8. Phospholipids form monolayer (on surface)/micelle/bilayer (in water) but triglycerides don’t;
41
Q

Describe the role of micelles in the absorption of fats into the cells lining the ileum.

A
  1. Micelles include bile salts and fatty acids;
  2. Make the fatty acids more soluble in water;
  3. Bring fatty acids to lining (of the ileum);
  4. Maintain high(er) concentration of fatty acids to cell lining (of the ileum):
  5. Fatty acids (absorbed) by diffusion
42
Q

Fatty acids - all have same structure but one thing varies -

A

the hydrocarbon tail - variable R group

Biology - Unit 1-4 (65 decks)

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