Zusammenfassung der Ressource
Biology Unit 2.5 - Proteins-their
functions and uses
- Proteins
- Protein molecules are made up of LONG CHAINS of AMINO
ACIDS. These long chains are folded to produce a specific shape
that enables other molecules to fit into the protein.
- Proteins act as...
- Hormones
- Antibodies
- Structural components of
tissues such as muscles
- Catalysts
- Enzymes
- The shape of an
enzyme is vital for the
enzyme's function
- High temperatures can change the shape
- Different enzymes work best
at different pH values.
- Some enzymes work outside the body cells
- The digestive enzymes are
produced by specialised cells in
glands and in the lining of the gut.
- The enzymes then pass out of the
cells into the gut where they come
into contact with food molecules
- They catalyse the breakdown of
large molecules into small
molecules
- Amylase is produced in the
salivary glands, the pancreas and
the small intestine
- This enzyme catalyses the breakdown
of starch into sugars in the mouth and
small intestine
- Protease enzymes are produced
by the stomach, the pancreas and
the small intestine.
- These enzymes catalyse the
breakdown of proteins into amino
acids in the stomach and small
intestine
- Lipase enzymes
are produced by
the pancreas and
small intestine.
- These enzymes catalyse the
breakdown of lipids (fats and
oils) into fatty acids and
glycerol in the small intestine
- The stomach produces
hydrochloric acid. The
enzymes in the stomach
work most effectively in
these acid conditions
- The liver produces bile, which is stored in the
gall bladder before being released into the
small intestine.
- Bile neutralises the acid
that was added to food in
the stomach
- This provides alkaline conditions in
which enzymes in the small intestine
work most effectively
- Some microorganisms produce enzymes that pass out of
the cells. These enzymes have many uses in the home and
in industry
- At home...
- Biological detergents may contain
protein-digesting and fat-digesting enzymes
(proteins and lipases)
- Biological detergents are more effective at low
temperatures than other types of detergents
- In industry...
- Proteases are used to 'pre-digest' the protein in
some baby food
- Carbohydrates are used to
convert starch into sugar syrup
- Isomerase is used to convert glucose syrup into fructose syrup,
which is much sweeter and therefore can be used in smaller
quantities in slimming foods
- In industry, enzymes are used to bring about reactions at
normal temperatures and pressures that would otherwise
require expensive, energy-demanding equipment. However
most enzymes are denatured at high temperatures and many
are costly to produce