TOPIC 1 : BIOLOGICAL MOLECULES Flashcards
State the definition of a Monosaccharide
Simple sugar monomer
State the definition of a Disaccharide
Two monosaccharides joined together by a glycosidic bond
State the definition of a Polysaccharide
Many monosaccharides joined together (more than 2)
Draw the structure of alpha and beta glucose
Beta: Hydroxyl group facing up
Alpha: Hydroxyl group facing down
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Draw the structure of ribose
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State the monosaccharides that make up sucrose
Alpha glucose and fructose
State the monosaccharides that make up Lactose
Alpha glucose and beta galactose
State the monosaccharides that make up Maltose
Two alpha glucose
Draw and label the condensation reaction between two alpha glucose molecules.
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Define Hydrolysis
Using water to break glycosidic bonds between subunits
Describe the structure of cellulose
- Long straight chains that don’t spiral (cellulose is unbrached)
- Made up of beta glucose with 1-4 glycosidic bonds where every other beta glucose is inverted for hydrogen bonding to take place.(cross-linking)
Describe the structure of starch
- Chain of alpha glucose monomers
- Made up of two Polysaccharides: Amylose and Amylopectin
- Amylopectin is branched with 1-4 and 1-6 glycosidic bonds it is compact with branches so can be hydrolysed quickly so energy can be released quickly
- Amylose is an unbrached molecule so is very compact with 1-4 Glycosidic bonds it is coiled and compact so it can store lots of energy in a small amount of space
Describe the structure of Glycogen
- Made up of alpha glucose monomers
- Has both 1-4 and 1-6 glycosidic bonds so it is branched
- It is a compact molecule so can store lots of energy but also can be hydrolyzed quicker as it has branches
State the difference between saturated and unsaturated fatty acids.
- In saturated fatty acids all carbons form single covalent bonds with hydrogen.
- In unsaturated fatty acids one or more carbon atoms is linked by a double bond (C=C)
Describe the properties of Saturated lipids
- Do not have double carbon bonds
- Higher melting point
- Solid at room temperature
Describe the properties of Unsaturated lipids
- Do have carbon double bonds
- Weaker intermolecular forces
- Lower melting pint
- Liquid at room temperature
Describe the structure and properties of Fibrous proteins
- Long straight chain polypeptides
- Very little tertiary/quarternary structure mainly secondary structure
- Occasional cross-linkages which form microfibres for tensile strength
- Insoluble in water
- Large molecules
- Repeated amino acid sequences
- Structural proteins
- Hydrophobic on the outside
Describe the structure and properties of Globular proteins
- Complex tertiary/quaternary structures
- Form colloids in water
- Uses include hormones, antibodies
- Soluble
- small molecules
- Hydrophillic on the outside
State how the structure of lipids relates to their role in Energy Storage
energy is released when triglycerides are oxidised in respiration (mass for mass they release twice as much energy as carbohydrates)
State how the structure of lipids relates to their role in Waterproofing
Lipids are hydrophobic therefore they repel water.
State how the structure of lipids relates to their role in Insulation
Lipids are poor thermal and ion conductors. Lipids found in adipose tissue under the skin to reduce heat loss. Myelin is a lipid found on neurones to insulate the neurone and speed up neurotransmission
State the difference between a phospholipid and triglyceride.
Phospholipids and triglycerides are very similar but for phospholipids one of the fatty acids is replaced with a phosphate group.
State how the structure of a phospholipid related to its function in the cell membrane.
The cell membrane is a phospholipid bilayer with hydrophilic head facing out and hydrophobic tails in the middle controlling the exchange of substances
Draw the basic structure of an amino acid.
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Draw and label the condensation reaction between neighbouring amino acids.
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Primary structure of protein
The order and number sequence of amino acids