Section 1 - Chapter 1: Biological Molecules Flashcards
What is a monomer? + example
- Smaller units from which larger molecules are made.
- e.g amino acid, monosaccharides, nucleotides
What is a Polymer?
- Molecules made from a large number of monomers
What is Polymerisation?
The process by which polymers are formed
What is the process called when Polymers turn to Monomers? (splits)
Hydrolysis -
- Breaks the chemical bond between 2 molecules and involves the use of water
- Disaccharides are split into monosaccharides
What is the process called when Monomers turn to Polymers?
Condensation
- Monomers join together to form a polymer
- Joins 2 molecules together with the formation of a chemical bond and involves the elimination of a water molecule
- A covalent bond is formed
- e.g 2 monosaccharides forms a disaccharide
What is a Monosaccharide? + example
- Single Sugar, sweet tasting/soluble
- Contain Carbon, Hydrogen and Oxygen
- Formula (CH2O)n
- Play an important role in cell reactions
- e.g fructose, glucose, galactose
What is a Disaccharide? + examples
- 2 Monosaccharides joined together
- E.g Maltose, Sucrose, Lactose
- C12H22O11
What is a Polysaccharide + examples?
- Lots of Monosaccharides joined together in a condensation reaction
- e.g glycogen, starch, cellulose
What is a Carbohydrate?
- Organic Molecules
- Containing 3 elements: carbon, hydrogen, oxygen
- The general formulae is (CH2O)n
- Ratio: C:H:O= 1:2:1
What is the structure of a Alpha glucose?
What are the reactive groups in a Monosaccharide?
- Carboxyl group: C=O
- Hydroxyl group: OH
What is the function of carbohydrates?
- Great source of energy
- Used commonly as a substrate for respiration
- Forms cell walls
What is the Structure of a Beta Glucose?
What are some examples of Carbohydrates?
- Pasta
- Rice
- Bread
- Starch
- Fructose
- Glucose
What are the characteristics of lipids?
- Contain carbon, hydrogen and oxygen
- Proportion of oxygen to carbon and hydrogen is smaller
- Insoluble in water
- Soluble in organic solvents (e.g alcohol)
What are some examples of lipids?
- Oils
- Triglycerides
- Waxes
What is the function of Nucleic Acids?
- To carry the genetic code for the production of proteins
What are some examples of Nucleic Acid?
- DNA
- RNA
What are the functions of protein
- Forms the structual components in plasma membranes
- Required for the structure, function, and regulation of tissues and organs
What are some examples of proteins
- Insulin
- Amylase
- Haemoglobin
- Keratin
What are the roles of lipids
- Source of energy - oxidised provides more than twice the energy as the same mass of carbohydrate + releases valuable water
- Waterproofing - insoluble in water
- Insulation - fats are slow conductors of heat. Below body surface = retains body heat
- Protection - Fat is often stored around delicate organs
What is the structure of triglycerides and what causes variation.
- Have 3 fatty acids combined to a glycerol molecule. Each fatty acid forms an ester bond with glycerol in a condensation reaction
- Glycerol molecule in triglycerides are the same but properties (variation) depends on the fatty acid tails: chain
- All fatty acid tails have carboxyl group + hydrocarbon chain
- No double bonds = saturated
- 1 double bond = monounsaturated, 2 more polyunsaturated
What is the structure of phospholipids
- Similar to triglyceride but 1 fatty acid is replaced by a phosphate
- Phospholipid made of 2 parts:
- Hydrophilic head - attracted to water
- Hydrophobic tails - orientates away from water
- When polar phospholipid molecules are placed in water they position so heads face water and tails are away from water
How is the structure of triglycerides suited to its function
- High ratio of energy storing carbon - hydrogen bonds - excellent source of energy
- Low mass to energy ratio - good storage molecule, energy stored in a smaller volume, animals dont carry much
- Large, Non-polar molecules - insoluble in water, storage is not affected by osmosis (water potential)
- High ratio of hydrogen to oxygen atoms- triglycerides release when oxidised, provides a source of water
How is the structure of phospholipids related to their properties
- Polar molecules - in aqueous environments form bilayers within cell-surface membranes
- Hydrophilic head helps hold the surface of the cell membrane
- The phospholipid structure helps to form glycolipids combining carbohydrates with the surface - Important in cell recognition
What are the 2 types of lipids
- Triglycerides and phospholipids
Where is Glycogen found
- Animals and bacteria (never plants)
- It is stored as small granules in muscles and liver
What is the monomer of glycogen and what is its bonds
- Alpha glucose
- 1-4, 1-6 glycosidic bonds
What is Glycogen’s structure
- Like starch it is branched