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Which part of an amino acid differs to introduce variation?
Amino Group (NH2)
Acid Group (COOH)
R Group
Reactions that break down molecules are called?
Catabolic reactions
Anabolic reaction
Enzymes that catalyse the breakage of peptide bonds are called?
Diastases
Lactases
Proteases
A peptide (covalent) bond forms between which parts of amino acids?
An acid group and an R group
An acid group and an amino group
An amino group and an R group
When amino acids join together it is called?
Synthesis
Hydrolysis
The name of many amino acids is?
Polypeptide
Dipeptide
There are 35 naturally occurring amino acids.
The specific sequence of amino acids is the?
Primary structure
Secondary structure
The polypeptide coiling into an alpha-helix or folding into a beta-pleated sheet is caused by?
Ionic bonding
Hydrogen bonds
Disulfide bridges
A disulfide bridge occurs between?
Cystine
Gylcine
The tertiary structure (proteins) is caused by which bonds?
Hydrophobic and hydrophilic interactions
Glycosidic bonds
Ester bonds
Hydrogen bonding
Tertiary bonding forms two structures of proteins?
Pigment
Fibrous
Globular
Globular proteins have which roles within the body?
Metabolic roles
Structural roles
fibrous proteins usually soluble ?
Quaternary structure is?
More than 1 polypeptide subunit joined together
Further coiling and folding of a polypeptide
How many polypeptide sub-units is haemoglobin made up of?
6
4
2
3
Collagen is a fibrous protein?
How many polypeptide chains is collagen made up of?
What are the 3 main amino acids making by collagen?
Glycine
Alanine
Proline
The role of haemoglobin is to
Transport O2 and CO2 around the body
Fight infection
Aid blood clotting
Haemoglobin contains a prosthetic group?
Glucose is a
Pentose sugar (5 carbon atoms)
Hexose sugar (6 carbon atoms)
In alpha glucose the hydrogen is above the hydroxyl on the 1st carbon in the ring.
Plants and animals can use beta glucose.
Monosaccharides join to form di/polysaccharides by?
Peptide bonds
The disaccharide of alpha glucose is?
Maltose
Amylose
Starch is made of?
Cellulose
Amylopectin
Glycogen
Structure of amylose?
Unbranched
Branched
Alpha-glucose
Beta-glucose
Coiled and compact
Structure of amylopectin?
Structure of cellulose?
Straight chains= fibrils
Starch is made of alpha-glucose and cellulose is made of beta glucose.
Starch is made of 1 polysaccharide, cellulose is made of 2.
Both starch and cellulose are insoluble and found in plants
Starch is for structural support, cellulose is an energy store.
Glycogen is the main energy store in animals.
Structure of glycogen?
Compact
Joined by ester bonds
Joined by 1,4 glycosidic bonds
Why has glycogen a compact and branched structure?
To provide support
For storage and breakdown
Cellulose forms straight chains linked by hydrogen bonds= microfibrils=macrofibrils for?
Structural support
Energy store
A triglyceride is made up of?
1 molecule of glycerol with 4 fatty acids
1 molecule of glycerol with 3 fatty acids
1 molecule of glycerol with 2 fatty acids
A Phospholipid is made up of?
1 molecule of glycerol with 3 fatty acids and a phosphate group
1 molecule of glycerol with 2 fatty acids and a phosphate group
The phosphate group is?
Hydrophilic (likes water)
Hydrophobic (dislikes water)
Triglycerides are used as a?
Molecules to stabilise the cell membrane
Energy storage molecule
Phospholipids make up the cell membrane bilayer as do not let water-soluble substances pass through due to?
No gaps for substances to pass through
Centre is hydrophobic (tails)
Outside layer is hydrophobic (heads)
Cholesterol stabilises bilayer by?
binding to hydrophobic tails packing them closer together
Creating an extra layer outside of the membrane
The test for proteins is the?
Biuret test
Ethanol emulsion test
Iodine test
Benedict's test
Positive result for starch using iodine solution is?
yellow/brown ----> blue/black
yellow/brown ----> purple/blue
yellow/brown ----> red/orange
The concentration of glucose say be determined by?
Benedict's solution
A colorimeter
A colorimeter works by?
Measuring the amount of light passing through the sample.
Comparing the colour to a defined scale.
The more Cu(II)SO4 used up in Benedict's test the more light will be transmitted.
Precipitation will be filtered out before using a colorimeter?