Module 1 - Biological Molecules Flashcards
Monosaccharides
Glucose, galactose, fructose
How are monosaccharides joined
condensation reaction
Bond in carbohydrate
1-4 glycosidic
Disaccharides
Maltose, lactose, sucrose
Disaccharides formula
c12h22o11
How are polymers seperated
hydrolysis
Polysaccharides
Starch, glycogen, cellulose
What are polysaccharides
Carbohydrates, many monosaccharides, joined by condensation reaction/ glycosidic bonds
Starch
Energy stores, alpha glucose, amylose=coiled, amylopectin=straight+branches
insoluble, compact/coiled, branched
Glycogen
Energy stores, alpha glucose, straight chain
insoluble, compact/coiled, branched
Cellulose
Beta glucose, cell wall, pleated, hydrogen bonds, microfibrils, macrofibrils, strong
Starch test
Iodine-blue/black
Reducing sugar test
Heat with Benedicts, turns brick-red
Non-reducing sugar test
Heat with benedicts, no change,
hydrochloric acid (hydrolyses glycosidic bond)
sodium hydrogen carbonate (neutralises solution)
heat with benedicts, brick-red
Globular proteins
Soluble, specific 3D shape, enzymes, hormones, antibodies
Fibrous
Strong, insoluble, collagen, keratin
Protein building blocks
Amino acids
Structure of amino acid
H
|
NH2 - C - COOH
|
R
How do amino acids differ
Different R groups
How are amino acids joined together
Condensation reaction between carboxyl and amine group,
peptide bond
Primary structure
Peptide bonds between amino acids
Secondary
Polypeptide chain coils to form helix, hydrogen bonds and microfibrils form beta pleated sheet
Tertiary
Secondary structure folds to form specific 3D structure
Quaternary
Made of more than 1 polypeptide chain
Test for protein
Add biuret, turns purple
Lock and key model
Active site is rigid, only complementary substrates bind
Induced fit model
Active site changes shape to fit the substrate
Affect of substrate concentration on enzyme activity
Increase substrate concentration, more chance of successful collisions, more chance of successful enzyme-substrate complex, increase rate of reaction
continues until all active sites are being used
Affect of enzyme concentration on enzyme activity
Increase enzyme concentration, more chance of collisions, more chance of enzyme-substrate complex, increase rate of reaction
Continues until all substrates are used up = maximum rate of reaction
Affect of temperature on enzyme activity
temperature increase, kinetic energy increase, more collisions, more chance of enzyme substrate complex, increase rate of reaction
after optimum breaks tertiary structure, active site changes, enzyme denatures, rate of reaction decreases
Affect of pH on enzyme activity
If change in pH away from the optimum bonds break, active site changes, enzyme denatured, rate of reaction decreases
Competitive inhibitors
Substance with complementary shape to enzyme active site, binds, blocks substrate from binding
Non-competitive inhibitors
Substance that binds to another part of the enzyme, changes shape of the enzyme active site, no longer complementary to substrate
Triglyceride structure
1 glycerol, 3 fatty acids
joined by condensation reaction, ester bonds
bond is COOC
saturated and unsaturated
Saturated fats
No double bonds, solid
Unsaturated fats
Double bonds, causes kink, liquid
Structure of phospholipid
1 glycerol, 2 fatty acids, 1 phosphate
phosphate forms a hydrophilic head, fatty acids form hydrophobic tail
forms phospholipid bilayer
What are nucleic acids?
Polymers made from nucleotides (DNA + RNA)
DNA
DeoxyRiboNucleic Acid
carries genes
DNA building blocks
Phosphate, deoxyribose sugar, nitrogenous base
adenine, thymine, cytosine, guanine
DNA structure
Double helix - acts as template in replication
nucleotides join via condensation reaction between phosphate and sugar
hydrogen bonds between the bases - weak so easy separation
double strand - compact
Sugar phosphate backbone - protects bases
DNA replication
Interphase
semi-conservative
Semi-conservative replication
DNA helicase breaks hydrogen bonds
2 template strands
free complementary bases line up with templates
DNA polymerase joins the sugar phosphate backbone
Evidence for semi-conservative replication
replicating bacteria either 15N or 14N
14N=light isotope
15N=heavy isotope
Bacterial DNA made from 15N have heavy density
Bacterial DNA made from 14N have light density
Experiment - both combined, produce half 15 half 14
RNA
Ribonucleic acid
mRNA + tRNA
single stranded
phosphate, ribose sugar, nitrogenous bases-AUCG
ATP
Adenine triphosphate ADP+Pi+energy=ATP condensation reaction using ATP synthase ATP=ADP+Pi+energy released hydrolysis using ATP hydrolase releases energy from its bonds
What makes ATP good
Immediate source
releases small amount of energy
Uses of ATP
Protein synthesis organelle synthesis DNA replication cell division active transport metabolic reactions movement maintaining body temperatures
Role of water
found in living organism - cytoplasm, xylem/phloem, tissue fluid
acts as habitat
Properties of water
Water molecules are dipolar
Hydrogen has +ve charge, oxygen has -ve charge
so, h20 molecules can form hydrogen bonds with each other
Role of water
Habitat- high specific heat capacity, lots of heat needed for evaporation
when water freezes it becomes ice, less dense, floats on top, insulating underneath for organisms
Solvent- h20 molecules dipolar, can separate based on charge, +ve hydrogen and -ve oxygen mix with counterparts on solution, dissolves, useful in cytoplasm, diffusion, phloem etc
Hydrostatic pressure - when pressurised provides strong pushing force, mass flow, helps turgidity in plants
Homeostasis - control body temp by sweating, heat from blood to evaporate, sweat made of hydrogen bonds, large amount of heat to evaporate, latent heat of vaporisation
Inorganic ions
Salts/minerals Inorganic = does not contain carbon, ion = charged sodium ions (Na+), chloride ions (Cl-)
