Biological Molecules Flashcards
Definition of monomer
Small units that make up larger molecules
Definition of polymers
They are large molecules made up of a large number of monomers
Carbohydrates and proteins,monomers are joined together by ___________ reactions,with the elimination of a water molecule
Condensation
Blinds between polymers can be broken down through________,using a water molecule
Hydrolysis
Two isomers of glucose
A-glucose
B-glucose
6 important properties of water in biology are
- It is a metabolite in which many metabolic reactions (condensation,hydrolysis and photosynthesis)
- It is the solvent where metabolic reactions occur (the cytoplasm is 70-95% water)
- Relatively high heat capacity (buffers temp change, large amount of energy is needed to raise temperature of large bodies of water,maintain a relatively stable temperature)
4.relatively high latent heat of vaporisation (loosing small amounts of water through evaporation has a cooling effect)
5.strong cohesion between water molecules (supports columns of water in xylem for the transpirations tread and produces surface tension where water meets air)
- Ice is less dense than water (lakes do not freeze completely so organisms not killed as temperature falls)
How are glycogen and starch formed
When many glucose units are condensed together through a chemical reaction.
The glucose unit which makes up glycogen and starch are a glucose
How are disaccharides formed?
suagrs whose molecules are form when hexose sugar molecules react together by means of a condensation reaction
Examples of disaccharides
Glucose + glucose = maltose
Glucose +fructose= sucrose
Glucose +galactose =lactose
Glucoses structure and function
Structure:
Hexose monosacharide with a ring structure
Two isomers, a glucose and b-glucose
Function:
Soluble molecule that is used for respiration,stored as glycogen or starch as energy reserves or used in structural molecules
Function of amylose and amylopectin
Stores energy
Function of glycogen
Energy store in animals
Stores excess glucose in muscle and liver cells
Function of cellulose
Provides structural support in plants
Prevents lysis during osmosis
Definition of saturated
Chain that contains no double bonds
Properties of triglycerides
Not water soluble
Saturated molecules are usually solid at room temp
They are synthesised by the formation of three ester bonds between 1 glycerol molecules and 3 fatty acids
Properties of phospholipids
They have a hydrophilic head and a hydrophobic tail
They form a phospholipid bilayer. (double layer of molecules or atoms that are closely packed together)
Function of triglycerides
Long hydrocarbon tail that stores energy
Breakdown products that can be used as a respiratory substrate
Can be stored without affecting water potential
How can the hydrophobic properties of lipids be utilised ?
They hydrophobic properties can be utilised in water proofing in biological organisms such as the cuticle of leaves, exoskeleton of some insects and bird feathers
What are the four main carbon-based molecules common to all life
Carbohydrates,lipids,proteins, nucleic acids
Which two types of biological molecules act as the main stores of energy
Carbohydrates and lipids
What are the units of a polymer called
Monomers
What are the monomers of the disaccharide sucrose
Glucose and fructose
What us an anion? Give an example
Negatively charged ion, such as nitrate ions (NO3-)
Which type of biological molecule forms the major part of plasma membranes
Lipids/ phospholipids
Give three named examples of globular proteins
Haemoglobin, insulin, enzymes (pepsin)
How can the presence of reducing sugars be measured quantitively?
Reagent test strips colorimetry
Which isomer of glucose makes up glycogen
A glucose
What are the three main groups of lipids
Triglycerides
Phospholipids
Cholesterol
What is the test for lipids
Emulsion test
Which types of molecules are triglycerides made of
Glycerol and fatty acids
Which type of lipid is common in plasma membranes
Phospholipids
Which three elements are commmon in plasma membranes
Carbon
Hydrogen
Oxygen
What makes lipids unsaturated
Carbon-carbon double bonds
Which chemical is used in the biochemical test for starch
Iodine/potassium iodide
what is starch made of
made of long chains of glucose and consists of two compounds \mylose and amylopectin
what is amylose
an unbranched polymer
features of starch (could come up as a six marker)
1)insoluble
2)does not affect water potential so water is not drawn into the cell by osmosis
3)is large and insoluble so it doesnt diffuse out of the cell
4)is compact;can store a lot in a small space
5)when hydrolysed it forms a glucose which is easily transported and readily used in respiration
6)the branched ends can be acted on by enzymes realsing glucose monomers
