2.2-molecules Flashcards
What test identifies proteins ?
biuret test : if proteins present, colour changes from light blue to lilac.
What are the roles of carbohydrates?
1) energy store
2) energy source
3) structural unit
What are carbohydrates ?
Organic compounds only comprised of C,H, and O
What is the general formula of monosaccharides ?
CnH2n0n
What are isomers?
They have the same formula but are arranged differently in space
What are three examples of monosaccharides ?
Fructose
Glucose
Galactose
What bonds are formed between carbohydrates?
Glycosidic bonds
What breaks apart glycosidic bonds?
The addition of water and enzymes to for a hydrolysis reaction.
What forms sucrose ?
a-glucose and fructose
What forms lactose?
a-glucose and beta galactose
What forms maltose ?
2 x alpha glucose
What is an example of w heteropolysaccharide?
Hyaluronic acid
Why are polysaccharides good energy stores ?
Glycogen and starch are compact which means they don’t take up a large amount of space; they occur coiled in dense granules within the cell.
Polysaccharides hold glucose molecules in chains so they can be easily snipped off by hydrolysis.
Why are polysaccharides less soluble than monosaccharides ?
1) their size
2) regions which could hydrogen bond with water were hidden inside molecule.
What does amylose sometimes do to make it hydrophobic ?
It forms a double helix which has a hydrophobic external surface.
What is the structure of amylose?
- long chain of a-glucose molecules
- glycosidic bonds between carbons 1 and 4
- spiral shape which hydrogen bonds hold in place
- hydroxyl groups in carbon 2 are inside cell so it’s less soluble.
Where is glycogen stored ?
Dense granules in muscle and liver cells
Where are amylose and amylopectin stored ?
dense granules in starch grains in cells.
What is the monomer of amylose ?
a-glucose
What is the monomer of glycogen ?
a-glucose
what is the monomer of cellulose ?
Beta glucose
What is the monomer of amylopectin ?
a-glucose
Is amylose branched?
No
Is amylopectin branched ?
Ye
Is glycogen branched ?
Ye
Is cellulose branched ?
Nope
What glycosidic bonds does amylose have?
a1-4
What glycosidic bonds does amylopectin have?
a1-4
a1-6
What glycosidic bonds does glycogen have ?
a1-4
a1-6
What glycosidic bonds does cellulose have ?
beta 1-4
Is amylose spiralled?
Ye boi
Is cellulose spiralled ?
No
Is amylopectin spiralled?
Yeah
What forms a microfibril?
60-70 cellulose chains bound together
How big are microfibrils?
10-30nm in diameter
What are macrofibrils?
Up to 400 microfibrils
What are lipids ?
Biological molecules made of C,H, and O.
What are the functions of lipids?
1) energy source
2) energy store
3) protection
4) buoyancy
5) insulation
What are triglycerides made of?
1 glycerol
2 fatty acids
What are phospholipids made of ?
Glycerol
Phosphate
2 fatty acids
What does amphipathic mean?
A molecule that has a hydrophobic and hydrophilic side
What is cholesterol ?
A steroid alcohol
Where is cholesterol found in phospholipids and why?
It’s small and hydrophobic so found near phospholipid tails.
What atoms are found in proteins ?
N, O, C, H and sometimes suphur.
Why are proteins needed in organisms ?
Growth and repair :
Enzymes
Hormones
Structural
What is the secondary structure of proteins ?
a helix or beta pleated sheet.
How can the structure of amino acids be determined ?
1) ab initio protein modelling
2) comparative protein modelling
What are the bonds in proteins from strongest to weakest?
Ionic
Disulphide
Hydrogen
What is the primary structure of proteins ?
The sequence and order of amino acids in a polypeptide chain.
what are the roles of water that relate to its properties?
solvent
transport medium
coolant
habitat
what are the unusual properties of water?
ice is less dense than water high specific heat capacity high latent heat of vaporisation solvent cohesion and surface tension
why does ice being less dense than water help organisms?
- aquatic organisms have a stable environment in which to live through winter
- ponds and other bodies of water are insulated against extreme cold.
why does water being a good solvent help organisms?
molecules and ions can react together in water eg in cytoplasm
molecules and ions can be transported around living things while being dissolved in water.
why does water’s high specific heat capacity help organisms?
- living things including prokaryotes and eukaryotes need a stable temperature for enzyme-controlled reactions to function.
- aquatic organisms need a stable environment in which to live.
why does water being wet help organisms?
- provides habitats
- major component of tissues
- reaction medium for chemical reactions
- effective transport medium
why does water’s cohesion and surface tension help organisms?
- columns of water in plant vascular tissue are pulled up the xylem tissue together from the roots.
- insects like pond skaters can skate on water.
what is a condensation reaction?
when 2 molecules are joined together with the REMOVAL of water
what is a hydrolysis reaction?
when 2 molecules are split apart with the ADDITION of water
what atoms are found in carbohydrates?
C, H, O
what atoms are found in lipids?
C, H, O
what atoms are found in nucleic acids?
C, H, O,N, P
what is the tertiary structure of proteins?
the overall 3D shape of the protein molecule - very precise shape held in place by bonds between amino acids.
what is the quaternary structure of a protein?
protein structure which consists of more than 1 polypeptide chain
how do h-bonds form in proteins?
between H atoms w/slight positive charge and other atoms with slight negative charges in hydroxyl, carboxyl, and amino groups.
how do disulfide bonds form in proteins?
between sulphurs in different R groups-strong covalent bonds.
how do ionic bonds form in proteins?
between carboxyl and amino groups which ionise into NH3+ and COO- groups.
how do hydrophobic and hydrophillic interactions occur in proteins?
hydrophobic parts associate in centre of polypeptide to avoid water, hydrophillic parts found at edge to be clsoe to water. causes twisting of amino acid chain.
What is an initio protein modelling?
Model built based on physical/ electrical properties of atoms in each amino acid in a sequence.
Can be multiple solutions to the same amino acid sequence.
What is comparative protein modelling?
Scanning amino acid sequence against database of solved structures+produces set of possible models which would match that sequence.
what bonding does cellulose have?
b1-4
what happens between adjacent fibrils of cellulose in cell walls?
h-bonds
why is the ability of water to act as a solvent important for the survival of organisms?
- medium for metabolic reactions
- allows ionic compounds to separate
- can absorb/take in minerals
- able to DILUTE toxic substances
- transport
what kind of bonds do triglycerides have?
ester bonds
what does a balanced diet mean?
having all the right food groups in all the right proportions
why does a diet high in lipids have a harmful effect on health?
- obesity
- more cholesterol–deposited in arterial walls–plaque–artery LUMEN narrows–high blood pressure, stroke, heart attack, etc
how do you test for lipids?
mix thoroughly with ethanol
add cold water
if white emulsion forms, test is positive
how is glucose well suited to its role in living organisms?
- soluble so can easily be transported
- small so can diffuse across cell membrane
- can be quickly broken down to release energy
how do you test for reducing sugar without a colorimeter?
add benedict's + heat forms precipitate--> blue to brick red concentration estimate from degree of colour change/comparison with known concentration OR centrifuge and weigh precipitate use standard curve
how do you modify benedicts for non reducing sugar?
heat with acid, then add alkali to neutralise, then do benedicts.
why is water having a high latent heat of evaporation good for organisms?
evaporation is an efficient cooling mechanism eg sweating
why does water being transparent help organisms?
allows underwater photosynthesis
why does water’s high density help organisms?
allows flotation
What does calcium do?
- involved in transmitting nerve impulses
- important in blood clotting and muscle contraction
- increases rigidity of bones, teeth, and cartilage
What does sodium do?
- involved in regulation of osmotic pressure, control of water levels in body fluid and maintenance of pH.
- important for generating nerve impulses
- contributes to muscle contraction.
What does potassium do?
- involved in control of water levels in body fluid+ maintenance of pH.
- assists active transport of materials across cell memebrane
- important for generating nerve impulses and muscle contraction
- generates healthy flowers+leaves in flowering plants
What does H+ do?
- Involved in photosynthesis and respiration
- involved in transport of O2 and CO2 in blood
- involved in regulation of blood pH.
What does ammonium do?
- component of amino acids, proteins, vitamins, and chlorophyll
- component of nitrogen cycle
- maintaining blood pH in human body
What does nitrate do?
- component of nitrogen cycle
- component of amino acids, proteins, vitamins, and chlorophyll
What does HCO3- do?
- regulation of blood pH
- transport of CO2 into+ out of blood
What does chloride do?
- regulates blood pH (chloride shift)
- helps in production of urine from kidney+maintenance of blood pH.
- uses to produce HCl in stomach.
What does phosphate do?
- component of nucleic acids, ATP, phospholipids, and some enzymes
- increases rigidity of bone, teeth+cartilage (calcium phosphate)
- helps root growth in plants
What does OH- do?
Regulates blood pH.
What is the phosphate ion?
PO4 3-
state 5 roles of cholesterol in living organisms
1) maintaining fluidity of cell membranes
2) making vitamin D
3) making bile
4) converted to steroid hormones
5) waterproofing skin
why is glycogen a good storage molecule?
compact-lots of energy per volume-energy dense
lots of branches for enzymes to attach
insoluble-doesn’t affect water potential of cell
easily hydrolysed
what bonding does glycogen have?
a1-4 and a1-6
what are the axissessesse (?) of a calibration curve?
percent transmittance/absorbance and concentration
what’s the link between chlorine and amylase?
chloride ion is a COFACTOR of amylase
what are the positions of hydrophobic and hydrophillic groups in haemoglobin?
hydrophillic on outside
hydrophobic r groups on inside
what is the haem group in haemoglobin acting as?
PROSTHETIC GROUP
what kind of bond forms between glycerol and fatty acid?
ester bond
how does heat affect the tertiary structure of a protein?
cause molecules to have more kinetic energy vibrate more namedbondsbreak change in 3D shape of protein protein denatures
what are 4 properties of collagen that make it good for ligaments between muscles and bones?
strong
flexible
insoluble
not elastic
what are 5 properties of cellulose that make it suitable for a plant cell wall?
insoluble high tensile strength-never say strong all alone!! unreactive/inert flexible can form h-bonds w neighbouring chains
what forms cellubiose?
b glucose +b glucose
what are bacteria cell walls made of?
peptodoglycan-long polysaccharide chains crosslinked by short peptide chains
what are exoskeletons made of?
chitin
what are examples of lipids?
triglycerides
phospholipids
glycolipids
cholesterol
what is a monounsaturated fatty acid?
one that has only 1 double CC bond
what is a polyunsaturated fatty acid?
one that has more than 1 double CC bond
where is cholesterol made in animals?
mainly the liver
what are examples of steroid hormones made from cholesterol?
testosterone
oestrogen
vitamin D
what is the secondary structure of proteins?
the coiling or folding of an amino acid chain, which arises often as a result of h bond formation between diff parts of the chain-mian forms = a helix and b pleated sheet.
what bonds form within proteins?
h bonds
ionic
disulfide
hydriphobic/hydrophillic interactions
what are the properties of fibrous proteins?
regular repetitive AA sequences
insoluble
form fibres
what are the properties of globular proteins?
spherical
soluble-hydrophobic on inside
specific shapes eg enzymes
what is the function of collagen?
to provide mechanical strength
what are examples of places collagen is found?
artery walls
tendons
bones
cartilage/connective tissue
why is keratin strong?
rich in cysteine: lots of disulfide bridges.
where is keratin found?
fingernails, hair, hoofs, horns, scales, fur, feathers.
what is the purpose of keratin?
mechanical protection
impermeable barrier to infection
waterproof
what makes elastin strong and extensible?
cross linking and coiling
where is elastin found?
skin
lungs
bladder
blood vessel walls
what is the quaternary structure of haemoglobin?
4 polypeptides: 2a, 2b. on each chain there’s a haem group.
what is a protein with an ion prosthetic group called?
conjugated protein
how many polypeptide chains is insulin made of?
2
is insulin soluble?
yeah
what is the structure of pepsin?
1 polypeptide chain, symmetrical tertiary structure
how do you test for starch?
add iodide solution-yellow brown to blue black.
WHAT DOES REPEATING EXPERIMENTS DO
ALLOWS YOU TO IDENTIFY OUTLIERS, IMPROVING RELIABILITY, LETTING YOU CALCULATE SPREAD OF RESULTS, AND ALLOWING CALCULATION OF THE MEAN.
DO PHOSPHOLIPIDS CONTAIN GLYCEROL
NO
DOES CHOLESTEROL CONTAIN ESTER BONDS
NO
WHAT MIGHT BE DIFFERENT ABOUT THE FAKE MEAT PRODUCED BY MICROORGANISMS COMPARED TO NORMAL MEAT ?
THE FAKE ONE WOULD HAVE LESS SATURATED FAT AND MORE UNSATURATED FAT.
WHAT DO ALPHA AND BETA SUBUNITS CONNOTE
THE QUATERNARY STRUCTURE!! THE DIFFERENT CHAINS.
WHAT DOES OVERALL 3D SHAPE CONNOTE
TERTIARY STRUCTURE
WHERE ARE HAEMOGLOBIN’S HYDROPHILLIC GROUPS?
ON THE OUTSIDE.
