Biological Molecules Flashcards
What type of bond holds two monosaccharides together? [1]
Glycosidic
Two monomers of alpha glucose form what disaccharide? [1]
Maltose
Glucose + Glucose -> X
Glucose + Fructose -> Y
Glucose + Galactose -> Z
Maltose
Sucrose
Galactose
Describe how you would test for a reducing sugar using the Benedicts Test [3]
- Add Benedicts reagent to your sample
- Heat strongly
- Positive result is a brick red colour
What type of reaction involves the breaking of a molecule by adding a molecule of water [1]
Hydrolysis
What type of reaction involves joining two monomers by removing a molecule of water [1]
Condensation
Starch is a polysaccharide, describe its structure [3]
- Monomers of alpha glucose
- 1,4 glyosidic bonds
- Branches every 30 units 1,6
What is the test for starch? [1]
Add iodine if starch present it will turn a blue-black colour
Give three reasons why starch is an ideal molecule for storage? [3]
- Compact so doesn’t take up too much space
- Insoluble so doesn’t affect the water potential
- Can be easily hydrolysed into molecules of glucose which can be used for energy
Describe the structure of Cellulose [3]
- Polymer chain of beta glucose with every other glucose molecule rotated about 180 (inverted)
- Chains run straight and parallel with one an other
- Chain is unbranched
Explain what is meant by micro fibrils [2]
- Due to the nature of chains running so straight and parallel hydrogen bonds can form which gives it added tensile strength
Where is cellulose found within a plant cell? [1]
Cell wall
Why does cellulose need to be strong [2]
To provide enough strength to the plant so it can stand up straight
What is the energy storage molecules in humans called? [1]
Glycogen
A triglyceride contains what two groups [2]
Three fatty acid tails
One molecule of glycerol
What is the test for a lipid [2]
Add ethanol, water and shake, if lipid present then a cloudy white emulsion will form
What additional group does a phospholipid have that a regular triglyceride does not? [1]
Phosphate Group
What makes a fatty acid unsaturated [1]
The presence of a carbon carbon double bond
How many carbons does a hexose sugar contain? [1]
6
How many carbons does a pentose sugar contain? [1]
5
Which part of the phospholipid is hydrophobic and why? [2]
The fatty acids tails, since they are non polar
What is the name given to the way phospholipids arrange themselves when in water? [1]
Bilayer
What is the bond called joining the fatty acids together called? [1]
Ester
What is a COOH group called? [1]
Carboxyl
What is an OH group called? [1]
Hydroxyl
Draw out the structure of an amino acid
H2N - C(R)(H) - COOH
What type of reaction joins two amino acids together? [1]
Condensation
Describe the primary structure of a protein [2]
The order by which the amino acids are arranged in
Describe the secondary structure of a protein [2]
The way and which the polypeptide chains is twisted and shaped - beta pleated sheet/alpha helicase
Describe the tertiary structure of a protein [2]
The overall 3-D shape of the polypeptide as a result of both primary and secondary structure
Describe the quaternary structure of a protein [2]
If there are more than one polypeptides present or if there are any prosthetic groups
What is the bond holding two amino acids together called? [1]
Peptide
What is the biuret test for proteins? [2]
Add NaOH to raise pH add some copper sulphate if a purple precipitate forms then a protein is present
What is a DNA nucleotide made from [3]
Deoxyribose Sugar
Organic Base
Phosphate Group
What base is complementary to Thymine? [1]
Adenine
Hoe do complementary base pairs attach to one another? [1]
Hydrogen Bonds
What is a nucleotide of RNA made from? [1]
Ribonucleic Acid
Phosphate Group
Organic Base
In RNA which base is complementary to Adenine? [1]
Uracil
