Chapter 1 Flashcards
Define Monomer
A single repeating unit
Define polymer
A chain of monomers
Define hydrolysis
A reaction where you add water to break a bond
Define condensation
Joining molecules which releases water
Give 4 examples of carbohydrates
sugars starch cellulose glycogen
Define metabolism
all the chemical reactions that occur in cells or in an organism
Define isomer
A version of a molecule
Give the monomer of the following polymers Carbohydrates Lipids Proteins DNA
monosaccharides fatty acids and glycerol amino acids nucleotides
Give examples of monosaccharides
Glucose Galactose Fructose
Give examples of disaccharides and say what they are made up of
Maltose - glucose + glucose Sucrose - glucose + fructose Lactose - glucose + glacatose
Name the 2 glucose isomers
Alpha Beta
What test is used to test of reducing sugars
Benedicks + heat
What is used to test for starch?
Iodine solution
How many carbon atoms are in a Triose Pentose Hexose
3 5 6
Explain the test for non reducing sugars
add sucrose to test tube add hydrochloric acid place in boiling water for 5 minutes add sodium hydrogencarbonate to neutralise the acid test pH add benedicks to test tube place in boiling water for 5 minutes record results
State the test for non reducing sugars
Hydrolysis Benedicks + heat to boiling
What is a bond between two glucose molecules called?
Glycosidic bond
What are carbohydrates made up of?
Carbon Hydrogen Oxygen
General formula of monosaccharides
C(H20)
Starch is made up of long chains of ——- glucose linked by ————- bonds
Alpha Gylcosidic
Chains in ——- can be branched or ———— . ————- chains are wound into tight coils
Starch Unbranched Unbranched
What is a monomer of a protein?
An amino acid
What is a polymer of a amino acids?
A polypeptide
What is the generalised structure of an amino acid?
H
How many types of amino acids are there?
20
What is the bond in a polypeptide?
A peptide bond
What is the name for 2 amino acids bonded together?
Dipeptide
What is the solution used to test for proteins? What is this made of?
Biuret solution Sodium hydroxide and copper 2 sulphate
What are the colour changes in a biuret test?
Blue to lilac (if present)
What is the primary structure of a protein and what does it do?
It is the number and sequence of amino acids in a polypeptide chain that determines the shape and function of the protein
What is the secondary structure - bonds and shape
Alpha helix coil Beta pleated sheet Hydrogen bonds
What is the tertiary structure- bonds, shape, examples
Further folding and coiling of the protein to give a more complex and specific 3-D shape Hydrogen bonds Ionic bonds Disulphide bonds Globular proteins - enzymes
What is the quaternary structure Bonds, examples structure
More than one polypeptide chain often with prosthetic groups Hydrogen bonds Ionic bonds Disulphide bonds Hormones - quaternary
Enzymes are ———- at the ———— level . They are ————- proteins that act as —————- ————- to speed up reactions. Enzymes ——— the ————— energy required for a reaction
Proteins Tertiary Globular Biological catalysts Lower Activation
What is the difference between the lock and key model and the induced fit model?
The lock and key model states that the substrate exactly fits into the enzyme but the induced fit model shows that the enzyme has to alter the active site in order to exactly fit the substrate.
How does an enzyme break a substrate into product molecules?(induced fit model)
Puts stress on the bonds of the substrate which breaks them
Name all the factors affecting enzyme action (6)
Temperature pH Substrate concentration Enzyme concentration Competitive inhibitors concentration Non competitive inhibitors concentration
Name the 2 ways of measuring rate of reaction
The formation of the product The disappearance of the substrate
Describe a temperature vs rate of reaction graph
As temperature increases so does the rate of reaction because the kinetic energy of the substrate increases, hence why enzymes at cooler temperatures are inactive. At 37 degrees the maximum of the graph is reached because it is the optimum temperature of the enzyme. Past 37 degrees the rate of reaction rapidly decreases because the enzymes are being denatured and the hydrogen bonds are being overcome by the heat and this means the shape of the active site is changed so the enzyme substrate complex cannot be formed
Describe a pH vs rate of reaction enzyme graph
pH changes alters the number of free hydrogen and hydroxide ions, which will affect the charge on the amino acid and hence leads to the denaturation of the active site Beyond the optimum the charges of the amino acids and hence the proteins is changed which disrupts the active site
Explain the affect of low enzyme concentration on the rate of reaction
There is a shortage of active sites because there are more substrate molecules than the enzyme, which means the substrate is in excess so there is a low rate of reaction
Explain the effect of medium enzyme concentration on the rate of reaction
The addition of enzymes means that there is the perfect amount of enzymes for substrates so all the active sites are filled and the optimum concentration is reached
Explain the effect of high enzyme concentrations on rate of reaction
As there are already enough active sites for all the substrate there is no additional effect of the extra enzymes
Explain the difference between a substrate concentration graph and a enzyme concentration graph
The enzymes are the limiting factor for a substrate concentration graph whereas the substrates are the limiting factor on the enzyme concentration graph
What do inhibitors do?
Slow down the enzyme rate of reaction
What do competitive inhibitors do?
Take the place of the substrate as they have a similar shape and then makes an enzyme inhibitor complex not a substrate enzyme complex so it slows down the rate of reaction
What do non competitive inhibitors do?
Change the shape of the active site by binding to another place in the enzyme which prevents the substrate from fitting so that means no enzyme substrate complex is formed
What are lipids made of?
Hydrogen carbon and oxygen
Are lipids soluble or insoluble in water?
Insoluble
Are lipids soluble or insoluble in ethanol?
Soluble
Name 4 roles of lipids
Source of energy Waterproofing Insulation Protection
Explain why lipids are good insulators
They have slow conduction of heat
Explain why lipids are good sources of energy
They have double the energy of carbohydrates
Explain how lipids are used for protection
They store fat around delicate organs for protection
What are triglycerides made from?
1 glycerol molecule and 3 fatty acid molecules bonded by an ester bond
What is a saturated fatty acid?
A fatty acid with no double carbon bond where there are as many atoms as there can be
Define mono-unsaturated
A fatty acid with only 1 double carbon bond which means only one more atom can be added
Define a polyunsaturated fatty acid
A fatty acid with 2 or mote double carbon bonds where many atoms could be added
Fatty acids are _____ or uncharged, hydro________ molecules
Non polar Hydrophobic
Describe the structure of a triglyceride:
Compact and good for storage Insoluble in water Excellent source of energy Fat source of metabolic water
What bond is formed between glycerol and fatty acids
Ester bond
What is a phospholipid made of
2 fatty acids, 1 phosphate group and 1 glycerol
Phospholipids are __________ but they have a phosphate head which is ——— and is hydrophilic
Non polar Polar
Chains in ——- can be branched or ———— . ————- chains are wound into tight coils
Starch Unbranched Unbranched
Explain 4 advantages of the structure of starch
They are large and insoluble so they dont diffuse out of the cell and dont affect the water potential of the cell Compact so a lot can be stored in small spaces When hydrolysed they make alpha glucose which is used for respiration and is easily transported The branched form has many ends which can be acted on by enzymes simultaneously
Explain the difference between the structure of starch and glycogen
Glycogen is more highly branched and makes shorter chains
Where is glycogen stored in animals
Liver and muscles
Explain 4 advantages of the structure of glycogen
Insoluble so it doesn’t dissolve out of cells Compact Can be broken down rapidly bc highly branched- produces alpha glucose which is good for animals with high metabolic rates Insoluble so it doesn’t affect water potential
What glucose is cellulose made of
Beta
Does cellulose form straight unbranched chains or branched coil chains
Straight unbranched chains
What bonds form between the chains for cellulose? What is the use of these?
Hydrogen chains Add to overall strenght
When cellulose is grouped together what does it form?
Microfibrils
When grouped together what do microfibres form
Fibre
Explain 3 advantages from the structure of cellulose
Strong bc of hydrogen cross linkages Form straight unbranched chains which are strong Molecules group to make fibres which add even more strength
