Unit 2(c) Proteins Flashcards
What is the chemical formula for ammonia?
NH3
What are some properties of ammonia?
- Ammonia is very soluble in water
* It dissolves to produce an alkaline solution (it is the only non metal gas that does this)
What is the general formula for amines?
CnH2n+1NH2
What functional group is present in amines?
Amino group - NH2
What two functional groups are present in amino acids?
Amino group and carboxyl group
What is the term for amino acids when the animo group and the carboxyl group are on the same carbon?
Alpha-amino acids
What are essential amino acids?
Amino acids which cannot be synthesised in the body by altering other amino acids. They must be present in the human diet
What are some sources of amino acids?
Meats and animal produce
What are proteins made of?
Amino acid monomers
How are proteins formed?
Condensation polymerisation - water eliminated
What is the name for the link between and amine group and an acid group?
Peptide link (CONH)
How are proteins broken down during digestion?
Hydrolysis
What process is used to analyse the products of hydrolysed proteins?
Chromatography
What is the formula for the Rf value?
Rf = distance run by spot / distance run by solvent
What are the two types of proteins?
Fibrous and globular
What are fibrous proteins?
They are long and thin because of the long polyamide chains
Why do fibrous proteins take their structure?
Intermolecular hydrogen bonding
What fibrous protein structure is observed if the hydrogen bonds are within the same chain?
Spiral/Helix structure
What fibrous protein structure is observed if hydrogen bonding occurs between different chains?
Sheet like structure
Give some examples of fibrous proteins
Keratins, elastins, collagens
What are globular proteins
They are spiral chain proteins folded into compact units
Are globular proteins soluble or insoluble in water?
Soluble, so they can move around in the bloodstream
Give some examples of globular proteins
Haemoglobin, insulin, enzymes, casein, and many hormones
What are enzymes?
Biological catalysts made of proteins.
Why are enzymes specific?
They only work on one substrate - ‘lock and key’
What happens when enzymes are denatured?
Hydrogen bonds are broken, active site changes shape
What happens to proteins during cooking?
Intermolecular bonds are broken, alters texture of a food
