Unit 8 Quiz 3 Flashcards
(19 cards)
Describe proteins.
They are very diverse in structure and function.
How are proteins formed?
They are formed into polymers (polypeptides) by joining monomers (amino acids) through dehydration synthesis reactions.
What do all amino acids have?
All amino acids have an amino group and a carboxyl group (which makes it an acid).
How many amino acids are there?
There are 20 amino acids which differ inly in their R groups.
What are the functions of proteins?
Proteins are catalysts, structural, contractile, transport communication, storage, defense.
How are polypeptides formed?
They are formed in a dehydration synthesis reaction that links the carboxyl group of one amino acid with the amino group of the next amino acid.
What is the linkage of amino acid groups called?
The linkage is called peptide bond.
How long are polypeptides?
Most polypeptides are at least 100 amino acids in length, but some can be over 1000.
What are proteins made of?
Proteins are made of one or more polypeptide chains precisely twisted, folded and coiled into a unique 3 - dimensional shape.
What does the shape of the protein include?
The unique shape includes a groove that is a binding site for a specific molecule.
What is denaturation?
Denaturation causes a protein to unravel and lose its unique shape and function.
How is denaturation caused?
It is caused by changes in pH, salt concentration or high temperatures.
What are catalysts?
Enzymes are proteins that speed up specific reactions without being consumed.
What is activation energy?
The energy that is needed to start a reaction, that the enzymes lower
How are some enzymes named?
Enzymes are sometimes named according to the substrates they act on with - ase as the ending.
What sugar does lactase break down?
Lactase breaks down lactose.
What are substrates?
Specific reactants that enzymes work on.
What is the active site and what does it do?
The active site is a unique area that the substrate fits, which squeezes the substrate and aids the reaction.
What can the squeezing action cause?
The squeezing action may weaken bonds to form two products or holds two reactants closer so that functional groups can interact.
