Biochemistry and cell organisation

Question 1

What is an inorganic molecule?

Answer 1

A molecule or ion that has no more than one carbon atom

Question 2

What is a micronutrient?

Answer 2

A mineral that is needed in minute/trace concentrations

Question 3

What is a macronutrient?

Answer 3

Minerals needed in small concentrations

Question 4

What is a dipole?

Answer 4

A polar molecule, with a positive and a negative charge, separated by a very small distance

Question 5

Describe a hydrolysis reaction.

Answer 5

When water is added to separate two or more molecules

Question 6

Describe a condensation reaction.

Answer 6

When water is taken away to join two or more molecules

Question 7

What is a monosaccharide?

Answer 7

Small, organic molecules that are the building blocks for larger carbohydrates.

Question 8

How are the names of monosaccharides determined?

Answer 8

By how many carbon atoms are in the molecule

Question 9

What is a disaccharide? How are they formed?

Answer 9

They are composed of two monosaccharide units bonded together with the formation of a glycosidic bind and the elimination of water.

Question 10

What are polysaccharides and how are try formed?

Answer 10

Large, complex polymers formed from very large numbers of monosaccharide units, linked by glycosidic bonds.

Question 11

How are polysaccharides linked?

Answer 11

Glycosidic bonds

Question 12

What is an isomer?

Answer 12

Molecules with the same chemical formulae but a different arrangement of atoms

Question 13

What is a monomer?

Answer 13

A single repeating unit of a polymer (a single molecule)

Question 14

What is a polymer?

Answer 14

A large molecule comprising repeated units of monomers bonded together

Question 15

What is a glycosidic bond held together by?

Answer 15

An oxygen atom

Question 16

How is a saturated fatty acid tail different to an unsaturated fatty acid tail?

Answer 16

The saturated tail has all of its’ binds taken up, it is a straight zig zag, solid at room temp. Whereas unsaturated tails has double bonds and is a kinky chain, lipids don’t solidify so easily.

Question 17

What does monounsaturated mean?

Answer 17

One double bond

Question 18

What the primary structure?

Answer 18

The order of amino acids and the shape that this forms

Question 19

Describe the secondary structure.

Answer 19

Folding of the polypeptide chains made of amino acids into alpha helix or beta pleated sheet

Question 20

Describe the tertiary structure

Answer 20

Complex folding, protein given a globular shape

Question 21

Describe the quaternary structure

Answer 21

Large proteins form complex molecules

Question 22

In a biuret test, if protein is present, what is the colour change?

Answer 22

Blue to purple

Question 23

How is a triglyceride formed?

Answer 23

Through the combination of a glycerol and 3 molecules of fatty acids. The fatty acids join via a condensation reaction.

Question 24

What is a macromolecule?

Answer 24

A large molecule made from many smaller ones

Question 25

What is a diner?

Answer 25

Two of the same molecule linked together

Question 26

What elements do all lipids contain?

Answer 26

Carbon, hydrogen, nitrogen

Question 27

What element do SOME lipids contain?

Answer 27

Phosphorus

Question 28

What elements do carbohydrates contain?

Answer 28

Hydrogen, carbon, oxygen

Question 29

How many carbon atoms does a triode have? Pentode? Hexose?

Answer 29

3, 5, 6

Question 30

Which is the most common hexose sugar?

Answer 30

Glucose

Question 31

What formula do all hexose sugars have?

Answer 31

C6H12O6

Question 32

Apart from glucose, give two other example of hexose molecules.

Answer 32

Fructose, galactose.

Question 33

What two isomers can glucose exist as?

Answer 33

Alpha and beta

Question 34

What do glucose molecules bind together to form?

Answer 34

Polymers

Question 35

What do the properties of polymers formed from glucose depend on?

Answer 35

Which isomer is present, alpha or beta?

Question 36

Give three examples of disaccharides.

Answer 36

Sucrose, maltose, lactose

Question 37

By what reaction are two glucose molecules joined?

Answer 37

Condensation

Question 38

What are the monosaccharides in sucrose?

Answer 38

Fructose and glucose

Question 39

What are the monosaccharides in maltose?

Answer 39

Alpha glucose + alpha glucose

Question 40

What are the monosaccharides in lactose?

Answer 40

Glucose and galactose

Question 41

What is a reducing sugar?

Answer 41

Any sugarcoat has carbonyl group that can be oxidised to a carboxylate acid group

Question 42

How do you know if a Benedicts test is negative? What does this tell you?

Answer 42

The solution will remain blue, it tells you that there are no reducing sugars present and so you can now test for non reducing sugars

Question 43

Name a non-reducing sugar.

Answer 43

Sucrose

Question 44

Why is glucose stored as starch?

Answer 44

It is insoluble so has no osmotic effect, it cannot diffuse out of the cell, it is a compact molecule and can be stored in a small space, it carries a lot of energy

Question 45

What two substances is starch made up of?

Answer 45

Amylose and amylopectin

Question 46

How is amylose formed?

Answer 46

By condensation reactions between alpha glucose

Question 47

How is amylopectin formed?

Answer 47

From condensation reactions between alpha glucose molecules

Question 48

What is the test for starch?

Answer 48

Iodine changes colour from brown to blue/black

Question 49

Is the starch test quantitative or qualitative?

Answer 49

Qualitative

Question 50

Give three properties of starch

Answer 50

Compact and so can be stored in small spaces, easily broken down by enzymes to release sugar, insoluble and so does not affect the water potential of the cell and therefore does not cause the movement of large amounts of water

Question 51

What is glycogen the main storage polysaccharide in?

Answer 51

Animals

Question 52

Give two properties of glycogen

Answer 52

Compact and can be hydrolysed into the sugar residues

Question 53

Where is cellulose present?

Answer 53

In plant cell walls

Question 54

What makes cellulose so strong?

Answer 54

The fact that a glucose molecule needs to flip through 180 degrees to react

Question 55

How are cellulose molecules held together?

Answer 55

By hydrogen bonds

Question 56

What is chitin? What is it the main component of?

Answer 56

A structural polysaccharide and is the main component of fungal walls and the exoskeletons of insects

Question 57

What makes each of the 20 amino acids unique?

Answer 57

The R group in the general formula

Question 58

What is the process in which amino acids are linked together to form polypeptide chains?

Answer 58

Their order is directed by the order of nucleotides in DNA and mRNA

Question 59

What are linked together to form polypeptide chains?

Answer 59

Amino acids

Question 60

What is meant by essential amino acids?

Answer 60

The 10 acids that must be taken in with our diet

Question 61

Give 8 physical properties of water

Answer 61

Solvent, metabolite, high specific heat capacity, high latent heat of vaporisation, has cohesion, high surface tension, high density, transparent

Question 62

What is an organic molecule?

Answer 62

Molecules that have a high proportion of carbon atoms