Module 2.1.2 Biological Molecules Flashcards
What are the 3 Monosaccharides?
Glucose
Galactose
Fructose
What are the 2 types of glucose?
Hexose form - Alpha & beta
What are the 2 types of galactose?
Hexose form - Alpha & beta
Is Fructose a pentose or hexose?
Pentose due to the shape but still has 6 carbons
What are the 3 disaccharides?
Maltose
Sucrose
Lactose
How are disaccharides bonded?
Glycosidic bonds
What is maltose made up of and what bonds do they form?
2 alpha glucose + 1:4 glycosidic bonds
What is sucrose made up of and what bonds do they form?
Alpha glucose & fructose + 1:2 glycosidic bonds
What is lactose made up of and what bonds do they form?
Beta glucose & Beta galactose + 1:2 glycosidic bonds
What is a disaccharide?
2 monosaccharides linked together with glycosidic bonds
What is a polysaccharide?
Many monosaccharides linked together via glycosidic bonds
What are the 3 polysaccharides?
Starch
Cellulose
Glycogen
What is starch & what bonds is it linked by?
A polymer of alpha glucose linked by 1:4 glycosidic bond
What are the 2 different types of starch?
Amylose & Amylopectin
What is the difference between amylose & amylopectin?
Amylose - helical (1:4 glycosidic bond)
Amylopectin - branched (1:4 + 1:6 glycosidic bond (at point of branch))
What is cellulose and what is it linked by?
A polymer of beta glucose (1:4 glycosidic bond) - linear chains cross linked via hydrogen bonds
What is glycogen & what bonds is it linked by?
A polymer of alpha glucose (1:4 + 1:6 glycosidic bonds (at point of branch))
What is glycogen and what bonds is it linked by?
A polymer of alpha glucose + (1:4 & 1:6 glycosidic bonds (at point of branch))
What type of reaction makes glycosidic bonds?
A condensation reaction (water is released)
What are the properties of water?
The oxygen in water is more electronegative than the hydrogen (the atoms spend more time orbiting oxygen)
Oxygen is slightly negative + hydrogen is slightly positive (unequal share of electrons)
Water is non polar (allows the molecules to form hydrogen bonds between the slightly positive hydrogen & slightly negative oxygen of the different water molecules)
Water is cohesive (the forces between water molecules) & adhesive (the forces between the water molecules & the surface it is attached to)
The hydrogen bonds are weak between the oxygen & hydrogen molecules but water forms many - strong
Density (ice is less dense so nutrients in the water below can still circulate)
Transparent
Has a high specific heat capacity
What are the different important functions of water?
Water is a solvent (polar substances can dissolve e.g. glucose but not non polar)
Water is a medium for chemical reactions
Water is a transport medium -> (animals - blood plasma, plants - (xylem for mineral ions & water), (phloem for dissolved sugars)
Water is a coolant (sweat - evaporation)
Water is a habitat (aquatic organisms)
Is a major component of all cells & has important roles in cells (e.g cytoplasm - animal & plant cells)
Has a role in synthesising & breaking down biological molecules (condensation & hydrolysis reactions)
What is an amino acid?
The monomers that make up proteins
What are amino acids made from?
An amine group
A Carboxyl group
A variable ‘R’ group
A hydrogen
How many amino acids are there?
20
What makes amino acids different from eachother?
The R group
What is the bond that joins two amino acids together?
A peptide bond
What is a dipeptide?
Two amino acids joined by a peptide bond
What is a polypeptide?
3 or more amino acids joined together by peptide bonds
What are the different structures of a protein?
Primary
Secondary
Tertiary
Quaternary
What is the primary structure of a protein?
The sequence of amino acids in the protein
What is the secondary structure of a protein?
The shape of the amino acid
Can either be an alpha helix or beta pleated sheet (determined by hydrogen bonding)
What is the tertiary structure of a protein?
The 3D shape of the protein
Either fibrous or globular
What is a globular protein & an example?
A spherical protein that is soluble in water & usually takes a metabolic role in the body
Haemoglobin -> water soluble globular protein consisting of 2 alpha helices & beta pleated sheets that each contain a haem group (prosthetic group) -> carries oxygen around the body
What are fibrous proteins and what is an example of one?
Thin & long proteins that usually have structural roles in the body
Collagen -> fibrous protein that is strong & found in bones, cartilage & connective tissue & the main component of tendons
What is the quaternary structure of a protein?
When a protein has multiple polypeptide chains & is held together by hydrogen bonding, disulphide links or ionic bonds
Can also contain prosthetic groups (E.g. in haemoglobin)
What is the reaction that synthesises the formation of a peptide bond?
Condensation reaction
What is the name of the reaction that synthesises the breakdown of a polypeptide into amino acids?
Hydrolysis reaction
What does a hydrolysis reaction need?
Water
What does a condensation reaction release?
Water molecule
What are lipids only soluble in?
Organic solvents e.g. alcohol
What are the 2 types of lipid?
Saturated & unsaturated
What is a saturated lipid & where would they be found?
Found in animal fats
A lipid that doesn’t contain double carbon bonds
What is an unsaturated lipid and where is it found?
Found in plants
Contains double carbon bonds (Kinked)
What are tryglycerides?
Lipid molecules that contain 1 molecule of glycerol & 3 fatty acid molecules
What bonds join triglycerides together & in what reaction?
Ester bonds in a condensation reaction
