1.Biological Molecules Flashcards
What is a
Covalent bond
Ionic bond
Hydrogen bond
Atoms share pair of electrons in their outer shell-once filled it’s stable
Ions with Opposite charges attract one another-electrostatic atttraction
When S -ve region is attracted to S +ve region of another polar molecule
What is polymerisation
Joining up of monomers to form polymers
What is a
Condensation reaction
Hydrolysis reaction
Removal of water to join monomers
Addition of water to split up polymers
What are carbohydrates made of
What’s a monosaccharide
What’s a disaccharide
Oxygen carbon hydrogen oxygen nitrogen
Individual building block of carbs
Pair of monosaccharides joined by a glycosidic Bond
What are the two isomers of glucose
Alpha glucose (down up down down)
Beta glucose (down up down up)
What is the test for reducing sugars
Heat Benedictus reagent with solution
Goes orange/brown
What’s the reaction and bond that forms when two monosaccharides are joined together
Condensation reaction and glycosidic bond
What Are the monomers that form
Maltose
Sucrose
lactose
A glucose + A glucose
A glucose + fructose
A glucose + b galactose
What’s the test for non reducing sugars
Heat with hydrochloride acid
Then heat with Benedictus solution
Why do you heat a non reducing sugar with HCL
To split up the disaccharides
What’s a polysaccharide
Many disaccharides joined together through condensation reactions
Facts about starch
Major energy storage
Most abundant in plants
Small grains
Found in tight coils making it compact
What’s the role of starch
Energy storage
Insoluble so doesn’t affect water potential, doesn’t diffuse out of cells
Very branched so when hydrolysed quick release of glucose
Easily transported
What’s the test for starch
Add iodine solution and it’ll go blue/ black
Facts about glycogen
Found in animals and bacteria
Shorter chains
Very branched
Small granules
What’s the role of glycogen
Energy storage
Insoluble, doesn’t draw in water
Compact-lots stored in small place
Simultaneously worked on by enzymes for quick release
Structure of cellulose
B glucose Straight chains Chains run parallel Hydrogen bonds between chains Macrofibrils, macrofibrils, cellulose Cross bridging
What’s the function of cellulose
Cell walls
Prevents cells from bursting
Exerts inwardly pressure
How is cellulose suited to function
Long straight unbranched chains Cross linked Add strength Rigid Fibres grouped together add strength
Facts about lipids
Contain oxygen carbon hydrogen
Insoluble in water
Soluble in organic solvents
Role of lipids
Cell membrane-fluidity/flexibility Source of energy-if oxidised more energy than carbs Water proofing-waxy cuticles Insulation-slow conductors Protection-organs
What forms a triglyceride?
What’s the bond an reaction
3 fatty acids and glycerol
Joined in condensation reaction to form Ester bond
How is triglycerides structure related to function
Insoluble in water-doesn’t affect water potential
High ratio of energy-in carbon/hrdogen bonds
Low mass to energy ratio-lots energy stored in small place
Facts about phospholipids
Hydrophilic head-associates with water
Hydrophobic tail-orients itself away from water
Group of phospholipids heads associate together and with water to form a lipid bilayer or hydrophobic tails
How is phospholipids structure related to function
Bilayer in water-hydrophobic barrier between environment and cell contents
Allows formation of glycolipids-cell recognition
What’s the test for lipids
Add ethanol Shake Add cold water Shake Goes cloudy
What are amino acids made of
What’s the bond that joins them together
Carboxyl group, amine group and R-group
Condensation raacion to form peptide bond
H H O
\ I /
N -C -C
/ I \
H R OH
What is the primary structure of a protein
Series of condensation reactions amino acids joined in process called polymerisation
The sequence of amino acids that forms a primary structure of proteins that determines the shape and function
What’s the secondary structure of a protein
Polypeptide chain twists into either alpha helix or beta pleated sheets due to localised hydrogen bonding
Whay happens in the tertiary structure of proteins
R groups of amino acids bond together to give a more complex 3D shape
Disulphides bridges
Ionic bonds
Hydrogen bond
Hydrophobic interactions
What happens in the quarternary structure
More than 2 polypeptide chains are linked and bond together via their R groups
Prosthetic groups associate with the molecules (non protein groups)
What’s the test for proteins
Add biuret reagents
Purple colour=protein
Facts about enzymes
Catalysts
Lower activation energy
Need substrate to collide and to have min amount of energy for reaction to occur
What’s the structure of enzymes
Globular proteins
Specific shape
Active site that’s lined with R groups and amino acids
Bonds temporarily with a substrate molecule
What effect does temperature have on enzyme action
Rise in temp = increase in kinetic energy Molecules move faster Collisions more frequent More successful collisions More e-s complexes Increase enzyme action
Further increase causes hydrogen bonds in enzyme to break
Denaturation is permanent shape change of active site-subrate dont fit
What’s the effect of oh on enzyme action
PH is hydrogen ion concentration
Each enzyme has own optimum
Either side of optimum the reaction slows down
Bonds in tertiary structure break and change
Active site changes shape
Sub rate no longer fit
Effect of enzyme conc on enzyme action
Excess of substrate-increase in number of enzymes will increase the rate of reaction proportionally
Limit of substrate-increase in enzymes will increase rate of reaction until no substrate left to work on
YEffect f substrate conc on enzyme action
Enzyme conc fixed-rate of reaction increases in proportion until no more free enzymes left as they become saturated
What’s an enzyme inhibitor?
What are the two types of inhibitor
Something that directly or indirectly interferes with the functioning of the active site
Competitive-binds to active site instead of substrate, not permanent bonding, the greater the conc of inhibitor the slower the reaction
Non competitive-binds to allosteric site, changes shape of enzyme and active site, substrate doesn’t fit, increasing conc of substrate doesn’t decrease effect of inhibitor
