Biological Compounds Topic 1 Flashcards
Name the 4 key inorganic ions for living organisms
Magnesium (Mg2+)
Iron (Fe2+)
Calcium (Ca2+)
Phosphate (PO4^3-)
Role of Mg2+ in plants?
Producing chlorophyll
Role of Fe2+ in animals
Used in haemoglobin, to transport oxygen
Role of PO4³- in living organisms
To produce ADP and ATP
Role of CA²+ in living organisms
Strengthen tissues eg bones and teeth in animals and cell walls in plants
Why is water a polar molecule?
The oxygen is more electronegative than the hydrogen. So O attracts electron density in the covalent bond more forming a δ- in O and a δ+ in H
Describe the hydrogen Bonding in water molecules
Weak Intermolecular forces of attraction form between a lone pair on the δ- O and a δ+ H on an adjacent molecule
What is a metabolite?
A molecule formed or used in metabolic reactions
Describe the role of water as a metabolite
Water is a reactant in photosynthesis and hydrolysis reactions. And is a product of aerobic respiration and condensation reactions
Why is waters high specific heat capacity important for organisms
Acts as a temperature buffer, preventing large changes in core temperature and maintaining optimum enzyme activity
Why is waters high latent heat of vaporisation important for organisms?
When water evaporates it has a cooling effect. Important for homeostasis, so organisms can lose heat by panting or sweating
Why is water important as a solvent for organisms
It is a polar universal solvent. Enabling chemical reactions to take place within cells, the transport or materials in the plasma and removal of metabolic waste
Why does water have a high surface tension/
Due to the ordered arrangement and cohesion of molecules at the surface or water
Why is the high surface tension of water important for organisms?
Enables the transport of water and nutrients through plant stems and small blood vessels in the body, and allows small insects to walk on the surface of water
What is a monosaccharide?
A simple sugar with the formula of Cn(H2O)n
Give an example of some monosaccharides
Fructose, Ribose, Deoxyribose, alpha/beta glucose, galactose
Draw alpha glucose
-OH on the far right is facing down
Draw beta glucose
-OH on the far right is facing up
What is the name of the bond formed when 2 monosaccharides react?
Glycosidic bond
What is a disaccharide?
Molecule formed by the condensation of 2 monosaccharides, forming a glycosidic bond. Formula (C12H22O11)
Give examples of disaccharides and how they’re formed
Sucrose - Glucose + Fructose
Maltose (2x alpha glucose)
Lactose - Glucose + Galactose
What is a polysaccharide?
A polymer of monosaccharides, formed by many condensation reactions
Give some examples of polysaccharides
Starch, Glycogen, Cellulose, Chitin
What is the function of starch?
Energy storage in plants
Describe the structure of starch
Polymer of alpha glucose monomers
2 forms - amylose and amylopectin
Amylose - 1-4 glycosidic bonds and unbranched
Amylopectin - 1-4/1-6 glycosidic bonds and branched
What is the function of glycogen?
Energy storage in animals
How does the structure of glycogen relate to its function?
It is highly branched, so it rapidly hydrolyses into glucose
Describe the structure and function of cellulose
Linear polysaccharide that is the main component of the cell wall in plants
Consists of many beta glucose molecules joined by beta 1-4 glycosidic bonds
Alternate glucose molecules rotated 180 degrees allowing hydrogen bonds between parallel chains forming myofibirils
Describe the structure and function of chitin
Linear polysaccharide found in the exoskeleton of insects and crustaceans as well as fungal cell walls
Consists of many beta glucose molecules with amino acid side chains joined by beta 1-4 glycosidic bonds
Alternate glucose molecules rotated 180 degrees allowing hydrogen bonds between parallel chains forming myofibirils
Explain how a triglyceride is formed
One molecule of glycerol forms ester bonds with 3 fatty acids via condensation reactions
Explain the importance of the structure of triglycerides to their function
- High energy to mass ration, high calorific value from oxidation, so useful energy store
- Insoluble, so it doesnt effect the water potential of cells and waterproofs them
- Thermal insulation, as they are a slow conductor of heat
- Buoyancy, from a lower density than water
What is a phospholipid?
Formed by the condensation of one molecule of glycerol, 2 of fatty acid and a phosphate group
Relate the structure of phospholipids to their function
Glycerol backbone attached to to hydrophobic fatty acid tails and one hydrophilic polar phosphate head:
- Forms phospholipid bilayer in water (component of cell membrane)
- Tails splay outwards - allowing for waterproofing, eg skin
Difference between saturated and unsaturated fats
Saturated - have no C=C bonds and are solid at room temp because they have strong intermolecular forces
Unsaturated - have one or more C=C bonds, and are liquid at room temp due to week intermolecular forces.
What is meant by low density lipoprotein (LDL)?
Combination of triglycerides from unsaturated fats and protein
Blocks receptor sites, reducing cholesterol absorption
Known as ‘bad’ lipoproteins
How do LDLs contribute to the risk of cardiovascular?
The high blood cholesterol level caused by LDLs leads to formation of athersclerosis plaques
Describe the general structure of an amino acid
Amine Group (-NH2)
Variable side chain (R)
Carboxyl group (-COOH)
H atom
How are polypeptides formed?
Many amino acid monomers join together in condensation reactions, forming peptide bonds (-CONH-)
