1 - Biological Molecules Flashcards
What is a mole?
A unit for measuring a substance
What is a molar solution?
The amount of solution that contains one mole of solute in each litre of solut
What does one mole contain?
The same amount that there is of carbon atoms in carbon-12
Condensation reaction
A reaction that produces water
Hydrolysis reaction
When polymers are broken down by the addition of water
α-glucose
2 hydrogen on the top, two hydroxides on the bottom
β-glucose
1 hydrogen, then a hydroxide on the top, one hydroxide and one hydrogen on the bottom (alternate ways)
General formula of monosaccharides
(CH2O)n
n can be any number from 3 - 7
Glucose + Glucose –>
Maltose
Glucose + Fructose –>
Sucrose
Glucose + Galactose –>
Lactose
What are monosaccharides joined by?
Glycosidic bonds formed by condensation reactions
Where is starch found?
In animal cells
What is starch made from
α-glucose homopolypeptide
Structure of starch
Made up of chains of alpha glucose molecules linked by glycosidic bonds that are formed by condensation reactions
How starch is related to its function
Insoluble - doesn’t effect water potential – water isn’t drawn in by osmosis
Large – doesn’t diffuse out of cells
Compact – lots can be stored in a small space
When hydrolysed forms α-glucose – easily transported and readily used in respiration
Branched form has many ends – each can be acted on by enzymes simultaneously meaning glucose monomers are realised very quickly
Why does starch have a curved structure?
It forms α 1-4 glycosidic bonds
Why is starch insoluble?
Forms α 1-4 glycosidic bonds. This gives it a curved structure, meaning all it OH groups are on the inside, making it insoluble
Where is glycogen found?
Animal cells, bacteria cells, but never plant cells
Structure of glycogen
Made up of chains of alpha glucose molecules linked by glycosidic bonds that are formed by condensation reactions
(shorter chains, but is more highly branched than starch)
How is glycogen suited to its function
Insoluble – does not draw water out by osmosis
Insoluble – does not diffuse out of cells
Compact – lots can be stored in a small space
More highly branched that starch – more enzymes can work simultaneously so it can be broken down into glucose monomers more readily.
What is the function of starch and glycogen?
Energy storage
What is the function of cellulose?
Provides support and rigidity
What is the structure of cellulose?
Has straight unbranched chains. These run parallel to each other, allowing hydrogen bonds to form cross-linkages between adjacent chains
How is cellulose structure linked to its function?
Made from β-glucose – can from long, straight, unbranched chains
Cellulose chains run parallel to one another and are cross-linked with hydrogen bonds – adds strength
Molecules are grouped to form microfibrils – provides yet more strength
What are triglycerides made from?
1 glycerol and 3 fatty acids
What er phospholipids made from?
1 glycerol, 1 phosphate molecule, and 2 fatty acids
How do you know if a lipid is saturated or unsaturated?
Saturated have no C=C bonds
Unsaturated have C=C bonds
What holds glycerol and fatty acids together?
Ester bonds
What do phospholipids form in water
A bilayer
What part of the phospholipid id attracted to water
Head - hydrophilic
Tail - hydrophobic
Why do phospholipids position themselves in this manner?
They are polar molecules
Primary structure of proteins
The order of amino acids
Secondary structure of proteins
A long polypeptide chain is twisted into a 3D shape of an α-helix. Hydrogen bonds form
Tertiary structure of proteins
The α-helix folded and twisted even more complex (often specific) shape
Disulfide bridges (bonds) – strong Ionic bonds – formed between carboxyl and amino groups. Weaker than disulfide bonds, easily broken by pH changes Hydrogen bonds – easily broken
Quaternary structure of proteins
The combination of many different polypeptide chains and associated non-proteins.
