Download Chapter-1-Structure-and-Variety-of-Protein

Higher Human
Unit 1: Cell Function and
Inheritance
Chapter 1: Structure and
variety of proteins
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Aim: To examine the structure of proteins and the various roles of protein
Learning Intentions
• To examine the primary, secondary and
tertiary structure of proteins.
• To revise and expand the role of proteins.
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Aim: To examine the structure of proteins and the various roles of protein
Protein Structure.
• Proteins are organic compounds.
• They always contain CARBON,
HYDROGEN and NITROGEN.
• Sometimes they also contain SULPHUR.
• These elements are built into molecules
called AMINO ACIDS.
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Aim: To examine the structure of proteins and the various roles of protein
There are about 20 types of
amino acid.
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Aim: To examine the structure of proteins and the various roles of protein
The structure of proteins.
• Proteins can be described by looking at
them in 3 ways...
– Using their
• Primary Structure
• Secondary Structure
• Tertiary Structure.
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Primary Structure – The
sequence of Amino Acids
• Amino acids are built into a particular
genetically determined sequence during
PROTEIN SYNTESIS (we will learn about
this in Ch3.
• This sequence is known as the PRIMARY
STRUCTURE of proteins
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Aim: To examine the structure of proteins and the various roles of protein
Peptide Bonds.
• Each protein is built up from large
numbers of amino acids.
• These sub-units are joined together into
chains by strong chemical links called
PEPTIDE BONDS.
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Aim: To examine the structure of proteins and the various roles of protein
The strong peptide bond
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Aim: To examine the structure of proteins and the various roles of protein
Each chain is called a polypeptide
chain = primary structure
Polypeptides usually
consist of hundreds of
amino acid molecules
linked together.
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Aim: To examine the structure of proteins and the various roles of protein
Secondary Structure – The
sequence of Amino Acids
• Weak chemical links called HYDROGEN
BONDS form between certain amino acids
in a polypeptide chain.
• This causes the chain to become coiled
and spiral (HELIX). This is the Seconday
structure!
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Aim: To examine the structure of proteins and the various roles of protein
Weak Hydrogen Bonds
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Aim: To examine the structure of proteins and the various roles of protein
Tertiary Structure
• Tertiary structure – polypeptides become
further linked by various cross-connections.
• The types of connections formed at this
stage are important, they determine final
structure and allow it to carry out a specific
function!
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Aim: To examine the structure of proteins and the various roles of protein
Recap: The Bonds
• Peptide bonds: join the amino acids together
in a protein... STRONG – PRIMARY
STRUCTURE
• Hydrogen bonds shape the protein chain.
This affects the protein shape... WEAK –
SECONDARY STRUCTURE
• Further cross-connections: Determines final
structure and is necessary to allow the
protein to carry out a specific function! –
TERTIARY STRUCTURE
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Aim: To examine the structure of proteins and the various roles of protein
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Aim: To examine the structure of proteins and the various roles of protein
Variety and Roles of proteins
There is an amaazing variety of proteins in living
things. Humans have over 10,00 proteins.
Proteins can either be:
» Fibrous e.g. actin and myosin
» Globular protein e.g. insulin
» Conjugated e.g. haemoglobin
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Aim: To examine the structure of proteins and the various roles of protein
There is an amazing variety of proteins in living
things. Humans have over 10,00 proteins.
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Aim: To examine the structure of proteins and the various roles of protein
All Enzymes are made of globular
proteins
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Aim: To examine the structure of proteins and the various roles of protein
Antibodies are also globular proteins
Antibodies
protect
the body
from
foreign
antigens!
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Aim: To examine the structure of proteins and the various roles of protein
Antibody
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Aim: To examine the structure of proteins and the various roles of protein
More jobs of proteins.
• FIBRINOGEN and PROTHROMBIN are proteins which
protect the body by clotting the blood at wounds.
• All membranes are made of proteins,
• The cell has a CYTOSKELETON which is made of protein.
E.g. Microvillus, spindle fibres, and cilia all keep their
shape because of their protein ‘skeletons’.
• Bone, tendons, ligaments, skin and hair are all made of
proteins such as collagen, elastin and keratin.
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Aim: To examine the structure of proteins and the various roles of protein
Have we achieved our Learning
Intentions.
• Can you.....
– describe the primary, secondary and tertiary
structure of proteins?
– Describe the role of protein structure in its
function.
– Discuss the role of proteins.
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