Proteins Flashcards
What are proteins made from?
Long chains from amino acids
How and when is a dipeptide formed?
When 2 amino acids join together
How and when is a polypeptide formed?
When more than 2 amino acids join together
How many polypeptides make up a protein?
One or more
Do different amino acids have the same variable group?
No
What’s amino acids general structure?
Carboxyl group - COOH
And amine/amino group - NH2
A carbon containing variable group - R
What number of amino acids are all living things sharing?
20
How do polypeptides form?
Condensation reaction
What is a condensation reaction and what happens?
A molecule of water is released and the bonds formed between 2 amino acids are called peptide bonds
What are the 4 structures of proteins?
Primary structure
Secondary structure
Tertiary structure
Quaternary structure
What’s the primary structure?
Sequence of amino acids in the polypeptide chain
What’s the secondary structure?
Polypeptide chain doesn’t remain flat and straight
Hydrogen bonds form between amino acids
Chain therefore coils into alpha helix or folded into beta pleated sheet
What’s the tertiary structure?
Proteins made up of several different polypeptide chains
Proteins final 3d structure
What binds hood each structure together?
Primary - peptide bonds between amino acids
Secondary - hydrogen bonds
Tertiary - ionic bonds (-&+ charges) disulfide bonds (2molecules of amino acids come close together the sulfur atom in 1 cysteine bond to other sulfur)
Hydrophobic and hydrophilic interactions and hydrogen bonds
Quaternary structure - can be influenced by all bonds
What’s a globular protein?
Round compact and made of multipolar polypeptide chains
Coiled up so that hydrophilic are on outside and hydrophobic are on inside
Soluble can easily transport fluids
E.g haemoglobin
What’s a fibrous protein?
Long insoluble polypeptide chains
Tightly coiled and held together by lots of bonds
Proteins strong often found in supportive tissue e.g collagen
