Brainscape's Knowledge GenomeTM

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


See full index

A-Level Biology - OCR A > 2.3 - Biological Molecules > Flashcards

2.3 - Biological Molecules Flashcards

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

State the general formula of a carbohydrate

A

Cₓ(H₂O)ᵧ

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

State the three main groups of carbohydrates

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

What is a monosaccharide?

A

A simple sugar with the general formula (CH₂O)ₙ where ₙ can be 3-7.
They are examples of monomers.
e.g. glucose, fructose, ribose

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

What are disaccharides?

A

‘Double sugars’ formed from two monosaccharides.

e.g. lactose, sucrose

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

What are polysaccharides?

A

Large molecules formed from many monosaccharides.

e.g. glycogen, cellulose, starch

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

How many carbons are contained in one molecule of pentose?

A

5 carbons.

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

How do ribose and deoxyribose differ?

A

Ribose has one H atom and one -OH group on Carbon-2, whereas deoxyribose has 2 H atoms and no -OH group on Carbon-2.

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

What type of sugar is glucose?

A

It is a hexose sugar.

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

What is the difference between alpha and beta glucose?

A

On alpha glucose the -OH group is BELOW Carbon-1.

On beta glucose the -OH group is ABOVE Carbon-1.

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

What reaction occurs when two monosaccharides join to form a disaccharide?

A

Condensation reaction.

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

What reaction is used to break apart polysaccharides and disaccharides?

A

Hydrolysis reaction.

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

How is maltose formed?

A

Two glucose molecules joined by an Alpha 1-4 Glycosidic bond.

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

How is sucrose formed?

A

One glucose molecule and a fructose molecule joined by an Alpha 1-4 glycosidic bond.

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

How is lactose formed?

A

Glucose and galactose joined by a Beta 1-4 glycosidic bond.

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

What is the major polysaccharide in animals?

A

Glycogen.

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

What is the major polysaccharides in plants?

A

Cellulose and starch.

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

What is starch made from?

A

Amylose and amylopectin polysaccharides.

  • 30% amylose (1-4 bonds)
  • 70% amylopectin (1-4 and 1-6 bonds)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is starch stored in plants?

A

Stored as intracellular grains in plastids.

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

What is cellulose made from?

A

Long chains of beta glucose molecules joined by beta 1-4 glycosidic bonds.

20
Q

How is cellulose structured?

A

Long glucose chains form rope-like microfibrils forming a network.

21
Q

What is glycogen made from?

A

Many alpha 1-6 glycosidic bonds producing a branched network.

22
Q

How is glycogen stored?

A

Small granules in the muscles an liver.

23
Q

How does the metabolic properties of glycogen differ from starch?

A

Glycogen is less dense and more soluble than starch - meaning it can be broken down more rapidly.

24
Q

What elements are proteins made from?

A

CHONS

25
Q

What functions do proteins provide?

A
  • Structure (connective tissue, skeletal fibre, hair, etc.)
  • Body regulation (enzymes and hormones)
  • Immunity (antibodies)
  • Energy
26
Q

Outline the basic structure of an amino acid

A
  • Amine group
  • R-Group
  • Carboxyl Group
27
Q

What kind of bond joins two amino acids together?

A

Peptide bond.

28
Q

What is a polypeptide?

A

10 or more amino acids in a chain.

29
Q

What is a protein?

A

One or more polypeptide chains folded into a highly specific 3D shape.

30
Q

What does primary structure of a protein involve?

A

Simple long chains with no intermolecular bonds/interactions.

31
Q

What does secondary structure of a protein involve?

A

Hydrogen bonds from causing the molecule to either fold or coil.
Forms either an alpha helix or beta pleating sheet.

32
Q

What does tertiary structure of a protein involve?

A
  • Hydrophilic/hydrophobic interactions
  • Hydrogen bonds
  • Ionic bonds
  • Disulphide bridges
33
Q

What does quaternary structure of a protein involve?

A

Same as tertiary but with two or more separate polypeptide chains interlinked.
e.g. haemoglobin (4 chains), insulin (12 chains).

34
Q

How do proteins become denatured?

A

Changes in temperature, pH or salt concentration can break the bonds which maintain the protein’s specific shape.

35
Q

What happens when proteins become denatured?

A
  • Bonds which maintain protein’s specific shape are
    broken.
  • Fibrous proteins lose their structural strength.
  • Globular proteins become insoluble and inactive.
36
Q

Outline the properties of a globular protein.

A
  • Soluble
  • Metabolically active
  • Mostly alpha helix
  • Forms globules (enzymes, hormones etc.)
37
Q

Outline the properties of a fibrous protein.

A
  • Insoluble
  • Structural
  • Mostly beta pleating sheet
  • Forms fibres (collagen, keratin etc.)
38
Q

Outline the structure and properties of haemoglobin.

A
  • Globular
  • 4 polypeptide subunits (2 alpha, 2 beta)
  • Most of structure is alpha helix
  • Each haem group (prosthetic group) contains Fe²⁺
    which is responsible for the colour.
  • Each molecule binds to 4 O₂ molecules.
39
Q

Outline the structure and properties of collagen.

A
  • Fibrous
  • Very strong
  • 3 polypeptide chains wound around each other
  • Each of the chains are coils held together by H bonds.
  • Each collagen molecule forms strong covalent bonds
    with other collagen molecules
  • Form collagen fibrils. Many collagen fibrils make a
    collagen fibre.
40
Q

Why is collagen so strong?

A
  • Glycine is small allowing close packing between
    molecules.
  • Collagen chains form a tight coil - they lie close to
    each other.
  • Many H bonds between R-Groups hold chains
    together very closely.
  • Strong covalent bonds with adjacent molecules
  • Staggered ends to parallel fibres prevent lines of
    weakness.
41
Q

Which elements do lipids contain?

A

CHO

42
Q

What is the most common form of lipid?

A

Triglyceride.

43
Q

How many water molecules are formed in the formation of a triglyceride?

A

3

44
Q

Why are some lipids liquids (oils) at room temperature?

A

They have unsaturated fatty acid chains. Double bonds cause kinks in the chains meaning there are fewer intermolecular forces between chains.

45
Q

Where in the cell do lipids play a major role?

A

The plasma membranes.

46
Q

Outline the functions of lipids.

A
  • Energy and metabolic water source
  • Buoyancy aid
  • Heat insulation
  • Waterproofing on hair/feathers
  • Electrical insulation
  • Protection of internal organs
47
Q

Outline the structure and function of cholesterol.

A
  • Small narrow molecule
  • 4 Carbon ring-based structure.
  • Regulates the fluidity of a membrane

A-Level Biology - OCR A (16 decks)

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