Bio topic 2

Primary structure

Primary structure

The specific sequence of amino acids that make up the polypeptide chain

Secondary structure

The 3D structure formed as a result of interactions between amino acids such as alpha helix or beta plated sheet

Tertiary structure

The more specific 3D folding of the secondary structure

Quaternary structure

The 3D arrangement of more than one tertiary polypeptide

What is an amino acid made of

Amino group, carboxyl group, hydrogen and R group

Monomers proteins made of

Amino acids

How do amino acids join

Condensation reaction forming a peptide bond

Bonds in primary structre

Peptide bond

Bonds in secondary structure

Hydrogen

Bonds in tertiary and quaternary structure

Hydrogen, ionic, disulphide

Amino acid structure

Carbon, hydrogen, R group, amino group, carboxylic acid group

What does peptide bond look like

H O

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N— C

Where you find polar R groups on protein

On the surface- hydrohphilic and attracted to water

Where you find non polar R groups on protein

Inside- hydrophobic and repel water

What are the 3 types of protein

Fibrous, globular, conjugated

Conjugated protein

Protein with another prosthetic group associated with their polypeptide chains

Fibrous protein

Polypeptide chains remain elongated

Little or no tertiary structure

Has repetitive sequences of amino acids

Has hydrophobic r groups on outside

Globular protein

Polypeptide chains are folded into spherical shape

Has tertiary structure

Does not have repetitive sequences of amino acids

Has hydrophilic r groups on outside

Overall function onpf fibrous protein

Important structural roles in organisms

Overall function of globular proteins

Important roles in metabolic reactions

Haemoglobin fibrous or globular

Globular

Collagen fibrous or globular

Fibrous

Is haemoglobin quaternary

Yes it has 4 polypeptide chains

Is collagen quaternary

Yes it has 3 polypeptide chains

Is haemoglobin conjugated

Yes it has a haem group

Is collagen conjugated

No

Is haemoglobin soluble

Yes

Is collagen soluble

No

Function of haemoglobin

Binds to oxygen and transports it

Collagen function

Structural strength and support

Polymer

Chain of many single monomers joined together in condensation reaction

How do plants and animals differ in amino acids they make

Plants can make all amino acids, animals only make some and get rest through diet called essential amino acids

Structure of phospholipid

Phosphate, glycerol and 2 fatty acids joined by ester bonds

Properties of phospholipid head

Hydrophilic, polar, soluble and attracts water

Properties of phospholipid tail

Hydrophobic, nonpolar, insoluble and repels water

Properties of cell membranes

Fluidity- gives membrane fluidity

Partially permeable- regulates substances in and out of cell

Flexibility

All parts of cell membrane

Phospholipid bilayer, glycoprotein, glycolipid, proteins, channel proteins, cholesterol

Function of glycoprotein

Role in cellular recognition and immune response

Act as receptors for hormones and neurotransmitters

Stabilise membrane

Function of glycolipid

Acts as surface receptors

Stabilise membrane structure

Function of protein in cell membrane

Role in cell signaling pathways and Stabilise membrane structure

Function of cholesterol in cell membrane

Disturbs close packing of phospholipids

Regulates membrane fluidity

Important for membrane stability

Function of channel protein

Control entry and removal of specifi molecules from a cell

Completely span bilayer