Brainscape's Knowledge GenomeTM

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


See full index

AS Biology OCR A > 3.3 Carbohydrates > Flashcards

3.3 Carbohydrates Flashcards

Chapter 3 - Biological Molecules

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

What are carbohydrates?

A

Organic polymers composed of the elements carbon, hydrogen, and oxygen, usually in the ratio Cx(H2O)y. Also known as saccharides or sugars.

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

What is the general formula of carbohydrates?

A

Cx(H2O)y

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

What is a monosaccharide and give examples?

A

A single sugar molecule. For example, glucose, fructose, and ribose.

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

What is a disaccharide and give examples?

A

A molecule comprising of two monosaccharides, joined together by a glycosidic bond. For example, lactose and fructose.

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

What is a polysaccharide and give examples?

A

A polymer made up of many sugar monomers (monosaccharides). For example, glycogen, cellulose, and starch.

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

What molecule is the basic building block of some biologically important large carbohydrates?

A

Glucose.

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

What is the chemical formula for glucose?

A

C6H12O6

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

What is a hexose monosaccharide and give examples?

A

A monosaccharide composed of six carbons. For example, glucose, fructose, and galactose.

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

What are the two structural variations of the glucose molecule?

A

Alpha (α) glucose and beta (β) glucose.

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

How can you tell the difference between the structures of alpha (α) glucose and beta (β) glucose?

A

OH group on alpha (α) glucose is below carbon 1 and OH group on beta (β) glucose is above carbon 1.

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

Why are glucose molecules polar and soluble?

A

Hydrogen bonds can form between the hydroxyl groups and water molecules.

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

Why is the solubility of glucose important?

A

Glucose can dissolve in the cytosol of the cell.

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

What is a condensation reaction?

A

A reaction between two molecules resulting in the formation of a larger molecule and the release of a water molecule.

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

What is a glycosidic bond?

A

A covalent bond between two monosaccharides.

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

What type of glycosidic bond is formed between two alpha (α) glucose molecules?

A

1,4-glycosidic bond.

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

What disaccharide is made when two alpha (α) glucose molecules react?

A

Maltose.

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

What is maltose?

A

Two glucose molecules linked together by a 1,4-glycosidic bond.

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

What disaccharide is made when an alpha (α) glucose molecule reacts with fructose?

A

Sucrose.

19
Q

What is sucrose?

A

A disaccharide made up of a fructose and a glucose monosaccharides.

20
Q

What disaccharide is made when an alpha (α) glucose molecule reacts with galactose?

A

Lactose.

21
Q

What is lactose?

A

A disaccharide made up of a galactose and a glucose monosaccharide.

22
Q

What is a pentose monosaccharide?

A

A monosaccharide composed of five carbons.

23
Q

Which two pentose sugars are important components of biological molecules?

A

Ribose, the sugar present in RNA nucleotides, and deoxyribose, the sugar present in DNA nucleotides.

24
Q

What is ribose?

A

The pentose monosaccharide present in RNA molecules.

25
Q

What is starch?

A

A polysaccharide formed from alpha glucose molecules either joined together to form amylose or amylopectin.

26
Q

Starch is a chemical energy store in which organism?

A

Plants.

27
Q

What are the two polysaccharides in starch?

A

Amylose and amylopectin.

28
Q

How is amylose formed?

A

Alpha glucose molecules joined together only by 1,4-glycosidic bonds.

29
Q

What is the structure of amylose?

A

The angle of the 1,4-glycosidic bond results in a helix shape which is further stabilised by hydrogen bonding within the molecule.

30
Q

What are the features of amylose?

A

More compact and less soluble than the glucose molecules used to make it.

31
Q

How is amylopectin formed?

A

Alpha glucose molecules joined together by 1,4-glycosidic bonds and 1,6-glycosidic bonds.

32
Q

What is the structure of amylopectin?

A

1,6-glycosidic bonds give parts of the polysaccharide a branched structure and the 1,4-glycosidic bonds give parts of the polysaccharide a straight chain structure.

33
Q

What is the chemical energy store in animals and fungi?

A

Glycogen.

34
Q

What is glycogen?

A

A branched polysaccharide formed from alpha glucose molecules.

35
Q

Why is glycogen an ideal storage for animals?

A

Glycogen forms more branches than amylopectin, which means it is more compact and less space is needed for it to be stored, as animals are mobile so need a lot of energy to be stored. Branches means there are many free ends where glucose molecules can be added or removed which speeds up the process of storing and releasing glucose molecules required by cells.

36
Q

What are the key properties of amylopectin and glycogen?

A
  • Insoluble.
  • Branched.
  • Compact.
37
Q

What is a hydrolysis reaction?

A

The breakdown of a molecule into two smaller molecules requiring the addition of a water molecule.

38
Q

Glucose is stored as starch by plants and as glycogen by animals, until it is needed for what process?

A

Respiration.

39
Q

What is cellulose?

A

A polysaccharide from beta glucose molecules where alternate beta glucose molecules are turned upside down.

40
Q

How is cellulose formed?

A

Alternate beta glucose molecules are turned upside down to allow the formation of a 1,4-glycosidic bond.

41
Q

What do cellulose molecules make when bonded together with hydrogen bonds?

A

Microfibrils.

42
Q

What do microfibrils make when joined together?

A

Macrofibrils.

43
Q

What do macrofibrils produce when combined together?

A

Cellulose fibres.

44
Q

What are the features of cellulose fibres?

A

Strong and insoluble and are used to make cell walls.

AS Biology OCR A (11 decks)

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