Module 2: Biological Molecules pt 1 Flashcards
What is a Monomer?
2 examples
A small, basic molecular unit
E.g: Monosaccharide or nuclear tide
What is a Polymer?
2 examples
A large, complex molecule made up of lots of monomers bonded together in a long chain
E.g: Proteins, polysaccharide, nucleic acid
How is a Polymer made
Formed from Monomers in condensation reaction.
This Forms a chemical bond between the monomers and releases a water molecule
What is Hydrolysis
Polymers are broken down into monomers by hydrolysis reactions.
=Breaking the chemical bond between the molecules using a water molecule
What are Macromolecules?
Complex molecules with a relatively large molecular mass
E.g: Proteins, some carbohydrates and lipids.
polymers are a group of macromolecule
What is a Cation
ion with positive charge
What is an Anion
Ion with negative charge
Role of inorganic Calcium Cation
(Ca2+)
Involved in transmission of nerve impulses at a synapse and muscle contraction
Role of Sodium Inorganic Cation
(Na+)
Needed for transmission of nerve impulses along neurone
and for reabsorption of glucose in the PCT of the nephron
Role of Potassium Inorganic Cation
(K+)
Used in guard cells to open stomata and activate enzymes needed for photosynthesis in plant cells
Role of Hydrogen Inorganic Cation
(H+)
Diffuse through ATP synthase to produce ATP
also a high concentration of H+ leads to low PH
Role of Ammonium Inorganic Cation
(NH4+)
Absorbed by root hair cells.
This is one source of Nitrogen for a plant, which it needs produce amino acids and nucleic acids
Role of Nitrate Inorganic Anion
(NO3-)
Also absorbed by plants as a source of nitrogen
Role of Hydrogen carbonate Inorganic Cation
(HCO3-)
Involved in transport of CO2 in the blood and also act as buffer in the blood
Role of Chloride Inorganic Cation
(Cl-)
Move into red blood cells to maintain a neutral charge, during CO2 transport
Role of Phosphate Inorganic Cation
(PO4^3-)
Needed for formation of ATP.
Also are part of a phospholipid molecule. in membrane
Role of Hydroxide Inorganic Cation
(OH-)
Help to form hydrogen bonds between molecules.
Also determine PH.
High concentration of OH- leads to a High PH
What’s the difference between alpha and beta glucose?
The position of the Hydrogen on the first carbon atom
AlpHa, the H Is higher
Beta, the H is Below the OH
What type of bond do monosaccharides form
Glycosidic bond
What is the role of starch
Main source of energy in plants
energy storage
Is starch soluble or insoluble
Insoluble
What are the two components of starch
Amylose and amylopectin
Structure of amylose and how it aids function
Unbranched long polymer of alpha glucose molecules.
1-4 glycosidic bonds, angled to cause helix structure to make it very compact for storage
Also stabilised by H bonds
Structure of amylopectin and how it aids function
1-4 bonds
1-6 bonds which cause branches to make it easier for enzymes to break them down
What is the test for starch?
What colours will it turn
-grind food into paste, add water, filter food particles
-add iodine in potassium iodide solution
-if starch is present, it will turn blue/black
-will remain orange/yellow if not
Function of glycogen
Main energy store in animals
Structure of glycogen
Polysaccharide of alpha glucose
1-4 glycosidic bonds
1-6 bonds cause many branches
Very compact
What type of glucose molecules is cellulose made from
Beta glucose
What are cellulose fibres made out of
Two Macrofibrils
What are cellulose macrofibrils made out of
Two microfibrils
What are Microfibrils
Approx 60 cellulose molecules become Cross linked by hydrogen bonds
What makes up plant Cell walls?
Cellulose
Structural advantages of cellulose
Insoluble
Tensile strength
unreactive
flexible
How to test for reducing sugars
-Heat sample with benedicts solution in excess
-if sample stays blue, there’s no reducing sugar present
-If sample forms brick red precipitate then a reducing sugar is present
How to test for non reducing sugars
-heat sample with dilute hydrochloric acid, then neutralise sample by adding sodium hydrogen carbonate. - Heat sample Benedicts reagent (carry on as normal test)
-if it stays blue, no reducing sugar is present
- if it forms brick red precipitate then a non-reducing sugar is present
How to make rest for reducing sugars quantitative
-transfer all solutions into cuvetted
-set colorimeter onto Red filter
-set coloromiter to measure absorption
-calibrate colorimeter using distilled water (each time before testing new solution
-measure all absorbances of solutions
-plot absorbances on graph against concentration/type of sugar
-draw line of beat fit/ calibration curve
-
how many different types of amino acids are there?
20
what bonds form between amino acids?
peptide bonds
how do peptide bonds form?
between OH of carboxyl group and H of amine group
releases water molecule
What are globular proteins?
-Spherical, water soluble protein
-functional role
-3D molecule
Structure and function of Fibrous proteins
Long, tough, rope shaped
-insoluble
-not very reactive
-not folded into 3D molecules
-have a more structural rather than functional role
What happens in the primary structure of protein structure
peptide bonds form between amino acids creating polypeptide chains
What happens in the secondary structure of protein structure
-Oxygen, Nitrogen, Hydrogen bonds form
-H Bonds form between polar -NH and -Co
-Form at different stages
-either coil into alpha helix or
-fold into beta pleated sheets
What happens in the Tertiary structure of protein Structure
-Coiled chain of amino acids is coiled even further bringing R groups closer
-R groups clump together
-hydrophobic R groups clump together
-Hydrophilic R groups push to outside
-If single polypeptide this is final structure
~R groups interact forming
-Ionic bonds between opposite charges
-Disulfide bonds
-Hydrogen bonds
-
What happens in the Quaternary structure of protein Structure
-Made of several polypeptide chains form together
-Final3D structure
-Influenced by bonds in tertiary structure
Function of catalase
-Makes sure Hydrogen peroxide doesn’t accumulate
-Is an Ezyme so catalyses reactions
Structure of catalase
-Quaternary protein
-4 haem prosthetic groups
-presance of iron II allows catalase to react with hydrogen peroxide
Function of Insulin
-helps regulate blood glucose levels
Structure of Insulin
- two polypeptides joined by Disulphide bonds
-precise shape to fit receptors
-6 Insulin form together in pancreas to form globular structure
Function of haemoglobin
Carry O2 in red blood cells
Structure of Haemoglobin
-2 alpha, 2 Beta subunits
-4 polypeptide chains
3 main examples of globular proteins
-Insulin
-haemoglobin
-catalase
3 main examples of fibrous proteins
-keratin
-Elastin
-Collagen
Collagen structure
-3 polypeptide chains wound round each other
-3 alpha helices
-every 3rd amino acid is glycine
-lots of H bonds form between polypeptide chains and cross links
-connects at end to form tropocollagen
-minerals can bind to increase rigidity
Function of collagen
-aggregate, chains come together to form tendons and ligaments
-provides structural support
Structure of keratin
-lots of cysteine containing sulfur
-so lots of Disulphide bonds/ bridges
-more Disulphide bonds = less flexible
Where is keratin Found?
-hair
-nails
-animal horns
-skin
Structure of Elastin
-made from stretchy tropoplastin
-Long stands held together by cross links
-contains hydrophobic R groups which Try to associaten(group together)
-Insoluble., unreactive, strong
Where is Elastin found
-Large blood vessels, skin, muscles, organs, alveoli, elastic fibres
Function of Elastin
-Converts tissue to original shape
-confers elasticity and strength to skin, muscles and organs around the body
-act as small strings
What is biuret Reagent made from
Sodium Hydroxide + Copper sulphate
How do you test for proteins
-3cm^3 food sol in test tube
-add 3cm^3 Dilute sodium Hydroxide
-MIX
-add 10 drops of Dilute copper(II) sulphate sol
-MIX (biuret reagent)
-turn purple/violet if protein present
-if no protein present, stays blue
Name for test for lipids
Emulsion test
How to perform emulsion test for lipids
-test substance + ethanol
-Shake
-add water
-milky colour indicates lipid
Difference between unsaturated saturated Fatty acids
Saturated have no double C=C bond
Solid at room temp
Unsaturated have at least one C=C bond
Usually oil (tails not straight line so not compact?)
What bonds form between Glycerol and fatty acids
Ester bonds
Functions of Tryglycerides
-Energy storage in plants and animals
-Carbon storage in bacterium
-cushioning
-thermal insulation
-buoyancy
Function of phospholipids
-make up phospholipids in bilayer plasma membrane
-control what enters cell
Function of Cholesterol
-positioned between phospholipids in cell membrane to maintain fluidity at different temperatures
-adds stability to membrane
-Vitamin D, steroid hormones, bile are all manufactured using cholesterol
structure of Triglycerides and how it aids its function
-3 fatty acid/hydrocarbon tails with lots of chemical energy when broken down
-Insoluble so doesn’t affect water potential
-one molecule of glycerol joined by ester bonds with 3 fatty acid tails
structure of Phospholipids and how it aids its function
-one glycerol molecule attached to phosphate group and two fatty acid tails
-hydrophobic fatty acid tails
-hydrophilic phosphate head
-this causes phospholipids to form a bilayer with heads on the outside and tails on the inside
-so water soluble substances can’t easily pass through
structure of Cholesterol and how it aids its function
-small size, flattened shape. Allowing it to fit between phospholipids and stop them from grouping
-bind to hydrophobic tails of phospholipids making phospholipids pack together, regulating fluidity
-Hydrocarbon ring structure attached to hydrocarbon tail and a polar hydroxyl group
What makes water a polar molecule
More electrons on oxygen atom, less electrons oh hydrogen atoms
:. Hydrogen partially positivev
Oxygen partially negative
What makes water a good solvent
-Water is polar
-Patially positive H end of water attracted to negative ion
-partially negative O end of water attracted to positive ion
:. Ions are completely surrounded
How does water being a good solvent help animals
Helps for strasport of substances
E.g blood, Cell sap in phloem
What makes water cohesive
Polar molecule so opposite charges attract to each other, forming Hydrogen bonds between each other
How does water being Cohesive and adhesive help living organisms
-Mass flow on xylem (capillary action)
-coheres stronger than it adheres so creates surgace tention
-can be used as a habitat
How does ice form from water
Ice structure
-Water freezes at 4°C
-Water molecules held further apart in ice due to the many hydrogen bonds formed (4 per molecule) creating a lattice structure
-created air gaps, making ice less dense then water
How does ice benefit animals
-ice forms insulating layer on top of water so that the water below doesn’t freeze
:. Fish don’t freeze
-animals also live on top of ice
Define specific heat capacity
Energy needed to raise 1kg of a substance by 1°C
What gives water a high Specific heat capacity
-it has many Hydrogen bonds
How does water having a high Specific heat capacity aid function and animals
-take a a lot of energy to heat up
-doesn’t experience rapid temperature changes
-Stable habitat for Organisms
Define latent heat of vaporisation
Energy required to turn liquid into gas
Wbu does water have a high latent heat of evaporation
-takes a lot of energy to break the many H bonds between water molecules
How does water having a hight latwnt heat of evaporation benefit animals
-A lot of energy is used up when water evaporates
:. Great as a cooling mechanism e.G: sweating
which monosaccharides make up sucrose
-glucose
-fructose
which monosaccharides make up maltose
2 alpha glucose molecules
