2. Amino Acids and Proteins Flashcards
Define polymer.
Large molecule made from joining many similar or identical monomers together.
Define assimilated.
Taken up by the body and used.
Define monomer.
Small molecule which can be joined with similar or identical molecules to form polymers.
Define condensation reaction.
A reaction joining two or more molecules involving the removal of water.
Define hydrolysis reaction.
A reaction breaking down a large molecule into its constituent parts by the hydrolysing the connecting bond with water.
What elements are amino acids made up of?
Nitrogen, carbon, hydrogen and oxygen.
Give examples of globular and structural proteins.
Globular proteins:
- Enzymes - biological catalysts that control biochemical reactions.
- Transport proteins such as haemoglobin.
- Signal proteins such as hormones.
- Contractile proteins such as actin and myosin. (Involved in muscle contraction).
- Defensive proteins such as antibodies.
Structural proteins:
- Keratin which is found in nails and hooves.
- Collagen which is found in tendons.
Draw the general structure of amino acids.
H H O | | | | N — C — C | | | H R OH ^ ^ ^\_\_ Carboxyl group. | |\_\_ R group - differs between amino acids. |\_\_ Amine group.
Describe the formation of a dipeptide.
- Two amino acids join together to form a dipeptide by a condensation reaction.
- The hydroxyl (OH) group from one amino acid reacts with the hydrogen from the amine group of another amino acid.
- This forms water and a peptide bond between the N in the amine group, and the C in the carboxyl group.
- This peptide bond creates the dipeptide.
How would you name 2, 3, 4, and 5 amino acids joined together?
2 = dipeptide. 3 = tripeptide. 3+ = polypeptide.
Draw a condensation reaction.
H H O H H O
| | | | | | | |
N — C — C N — C — C
| | | | | |
H R1 OH H R2 H
|_________|—–> H2O
|
V
H H O H H O
| | | | | | | |
N — C — C — N — C — C
| | | |
H R1 R2 H
Most of the food we eat is composed of _________, which are too ______ to be __________ into the __________ through the _____________________. During ______, _______ break down (__________) __________. Once _________, __________ molecules can be ___________.
Most of the food we eat is composed of POLYMERS which are too LARGE to be ABSORBED into the BLOODSTREAM through the SMALL INTESTINE MEMBRANE. During DIGESTION, ENZYMES break down (HYDROLYSE) POLYMERS. Once ABSORBED, SMALLER molecules can be ASSIMILATED.
Draw a hydrolysis reaction.
H H O H H O
| | | | | | | |
N — C — C — N — C — C
| | | |
H R1 R2
|_________|
Amino acids are the basic ______ of __________, which combine to make a ________ called a _________. Many amino acids join together in ___________ via _________ reactions to make a _______________ chain. A _________ chain will always have a ________ group at one end, and a ________ group at the other end. The number of _________ bonds will always be __________ than the number of amino acids. The ______ in a __________ chain is determined by the _____________. (_______ sequence = _______ of amino acids).
Amino acids are the basic MONOMER of PROTEINS which combine to make a POLYMER called a POLYPEPTIDE. Many amino acids join together in POLYMERISATION via CONDENSATION reactions to make a POLYPEPTIDE chain. A POLYPEPTIDE chain will always have aN AMINE group at one end, and a CARBOXYL group at the other end. The number of PEPTIDE bonds will always be ONE LESS than the number of amino acids. The ORDER in a POLYPEPTIDE chain is determined by the DNA BASE SEQUENCE (TGAC sequence = ORDER of amino acids).
How many levels of protein structure are there, and what are they called?
Four: Primary 1^o Secondary 2^o Tertiary 3^o Quaternary 4^o
