Flashcards
proteins
Cards in this deck (18)
- 1protein functions/ typesenzymatic (hexokinase
structural (collagen)
transport (haemoglobin)
storage
receptor - 2hexokinasecatalyses glycolysis
- 3amino acid structure-side chain (R)
-carboxyl group
-Amino group - 4peptide bondo=C-N-h
- 5size>20-27000
-average 500 - 6How do proteins bind to other molecules?They make many precise weak interactions with their target
- H bonds, ionic bonds, hydrophobic interactions. - 7example of protein bindingHexokinase binds ATP or ADP via ionic bonds to the
negatively charged phosphate groups, H bonds to the OH
groups of the ribose, H bonds to the N atoms of the
adenine and hydrophobic interactions with the adenine ring - 8Protein domainsindependent units of function and
evolution - 9relationship between structure and functionenzymes specifity to substrates
antibodies - 10antibody structure related to functionn 2
heavy and 2 light chains
joined by disulfide
bridges; both types of
chain have variable and
constant regions. Antigen
specificity is conferred by
the variable regions.
An antibody recognizes just
a small part of the antigen
called the epitope - 11prosethetic groupshaem group in haemoglobin
- 12How is protein function regulated?Protein conformation is flexible, regulatory proteins can
occur in 2 or more conformations with different properties
e.g hexokinase and glucokinase ; glycolysis regulated differently in muscle and liver - 13Membrane proteinsMembrane proteins can play many functions, such as cell-cell recognition,
signal transduction via hormone receptors, and transport - 14Rhodopsin– the protein opsin bound to the cofactor retinal
– is a key part of the visual system. In the eye’s rod and
cone cells it absorbs light and triggers nerve impulses to the
brain, i.e. it is a receptor for light. - 15Bacteriorhodopsinis a protein that acts as a proton
pump by capturing light energy and using it to
transport protons across the membrane and out of the
cell. The resulting proton gradient is subsequently
converted into chemical energy (ATP) as the protons
move back into the cell. - 16Bacteriorhodopsin & rhodopsinThese two proteins have similar structures,
different sequences and very different functions. - 17fibrous proteinexample:
Collagen in connective tissue - three collagen helices coiled
together, high tensile strength - 18summaryEnzymes catalyse reactions by binding their substrates at
the active site and reducing the reaction activation energy.
Antibodies have the capacity to recognize any molecule
because the amino acid sequence in the antigen-binding
site is highly variable.
Globins are related proteins with very similar structures but
different functions.
Some proteins require non-protein parts to function.
Membrane proteins (receptors, transporters etc) have
hydrophobic surfaces in contact with the membrane lipids.
The structure of fibrous proteins can contribute strength or
flexibility.
Information
- Description
- Flashcards on proteins, created by KirstyRM on 03/04/2014.
- Created by
- KirstyRM · Apr 2014
- Updated
- Feb 19, 2016
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