As Biology-Proteins

Front 1

What process joins amino acids together?

Back 1

Polymerisation

Front 2

What is a chain of amino acids called?

Back 2

A polypeptide chain

Front 3

What have to be combined to make a protein?

Back 3

Polypeptides

Front 4

What is the chemical formula for the amino group in an amino acid?

Back 4

NH2

Front 5

What is the chemical formula for the carboxylic group in an amino acid?

Back 5

COOH

Front 6

What elements are found within the R group?

Back 6

Hydrogen

Oxygen

Nitrogen

Sulphur

Carbon

Front 7

What does the joining of two amino acids form?

Back 7

Dipeptide joined by a peptide bond

Front 8

What process joins two amino acids together, how?

Back 8

Condensation by removing a water molecule

Front 9

How is water made during the condensation reaction between two amino acids?

Back 9

Made by combining OH from carboxylic group of one amino acid and a H from the amino group of the other amino acid

Front 10

How is the primary structure of a protein made?

Back 10

Many amino acid monomers joined through polymerisation

Front 11

Describe the primary structure of a protein

Back 11

Large number of amino acids arranged in a sequence to form a polypeptide chain

Front 12

What does the primary structure of a protein determine?

Why?

Back 12

The ultimate shape of the protein and hence its function.

If the sequence of amino acids differ, the bonds made in the tertiary structure change which therefore changes the overall shape

Front 13

How is the secondary structure formed?

Back 13

The -NH group has an overall positive charge due to hydrogen to the right of the peptide bond

The -C=O group has an overall negative charge due to oxygen to the left of the peptide bond

These two groups therefore readily form a weak hydrogen bond

This causes the long polypeptide chain to be twisted into a 3D shape known as an alpha helix

Front 14

What two things are formed in secondary structure of a protein?

Back 14

Alpha helix

Beta pleated sheet

Front 15

How is the tertiary structure formed?

Back 15

The alpha helices of the secondary structure can be twisted and folded to create a unique, 3D structure known as the tertiary structure

Front 16

Name the three bonds that hold the tertiary structure together in order of strength from weakest to strongest

Back 16

Hydrogen

Ionic-Broken by changes in pH

Disulphide

Front 17

Why is the 3-D shape (tertiary structure) of the protein important?

Back 17

Determines their function

It makes the protein distinctive and allows it to recognise and be recognised by other molecules.

It can therefore interact with them in a very specific way.

Front 18

What is the quaternary structure of a protein?

Back 18

Numerous individual polypeptide chains that are linked in various ways, a very complex structure that only the larger proteins have

Front 19

Give an example of a protein that has a quaternary structure

Back 19

Haemoglobin

Front 20

What is the most reliable protein test?

Back 20

The Biuret test-Detects peptide bonds

1. Measure equal amounts of sample and sodium hydroxide to a test tube

2. Add a few drops of dilute copper sulphate and mix

3. If the solution turns purple it means there is a protein present

Front 21

What functions do fibrous proteins have such as collagen

Back 21

Structural functions

Front 22

What functions do globular proteins have such as enzymes and haemoglobin?

Back 22

Metabolic functions