96 terms


What is the order of importance of energy sources?
Carbohydrates, fats, proteins, nucleic acids
What are carbohydrates made of?
C, H, O
what is the role of carbohydrates
transporters of energy
what is the most important carbohydrate
what forms does glucose exist in
linear-carbonyl group on C1, circular,
what is a monosaccharide and example
simple sugar molecule, glucose
what makes maltose
2 glucose
what makes lactose
glucose and galactose
what makes sucrose
fructose and glucose
what are the common monosacharides?
glucose, fructose, galactose
what are the common disaccharides?
sucrose, maltose, lactose
what are the limits for the levels of glucose within the bloodstream
between 4 and 8mM
what is hypoglycaemic?
blood glucose below 4mM
what is hyperglycaemic?
blood glucose higher than 8mM
how does the body regulate blood glucose levels?
hormones including glucagon, insulin, norepinephrine (adrenaline)
what is diabetes?
lacking ability to synthesis insulin and therefore unable to control blood sugar levels
what are the most common polysaccharides of glucose?
glycogen, starch, cellulose
what is glycogen
energy reservoir stored in skeletal muscle and liver
where is starch found
only in plants
what type of bond does starch contain
alpha 1,4-glycosidic bond
what type of bond does glycogen contain
alpha 1,4- glycosidic linkages and alpha 1,6- linkages forming side branches
what is the importance of the bonds in glycogen
maximises the number of ends available for digestion by enzymes that catalyse the breakdown of glycogen, more free ends=faster synthesis/break down
what is the difference in cellulose bonds
it uses beta 1,4- glycosidic linkages which humans are unable to break down
what is fibre
cellulose, unable to be digested and is inert as an energy source
what is the isomer of glucose and how does it differ
fructose, carbonyl group on carbon 2
what is an epimer of glucose and how does it differ
galactose, identical except for H and OH groups on C4 rotates 180 degrees
what is the difference in energy released by the monosaccharides glucose, fructose and galactose
none only the pathways differ
when does the body use fats for energy
when the supply of glucose decreases due to dieting, starvation or extended period between eating
what are lipids/fats composed of?
C, H, O
what is an example of a free fatty acid?
palmitic acid
how is palmitic acid composed
16 carbons with a carboxyl group at one end with a long hydrocarbon chain
what is a saturated fatty acid
fatty acid chain with no double bonds- all carbons are saturated with hydrogen atoms
what is an unsaturated fatty acid
contains at least one double bond
what is the notation for palmitic acid
what would 24:3 mean when describing fatty acids
24 carbons long and 3 double bonds
what form do the fats in membranes exist as
diglyceride or diacylglycerol
what are acyl groups
fatty acids chains
what is glycerol
three carbon sugar possessing three alcohol groups
what is a monacylglycerol/monoglyceride
one fatty acid joined to a glycerol molecule
where are triglycerides found
fat storage cells- adipocytes that make up adipose tissue
what are lipids
hydrophobic molecules
what do lipids include
fats, oils, waxes
what is the difference between fats, oils and waxes
composition of the molecules and degree of saturation
what type of fatty acid is more likely to pack together
what is butter composed of
saturated fatty acids
what is vegetable oil composed of
unsaturated fatty acids
what are fatty acids oxidised/broken down to
carbon dioxide and water and energy
why are fatty acids an efficient form of storing energy
molecule is highly reduced, light-less dense than water, hydrophobic- doesn't need to be dissolved in water for storage, completely oxidised to form Co2 doesn't form toxic products
what are steroids
lipids that are formed from four or five ring structures
what do steroids include
cholesterol, hormones-testosterone, progesterone, oestradiol
what are the functions of lipids
energy, storage, insulation, hormones
when do you break down proteins for energy
when you are starving and have used up sugars and fats
what functions do proteins serve
enzymes, transport (haemoglobin), storage, movement, structure, signalling (insulin, glucagon), regulatory, protective (immunoglobulins, antibodies)
what are proteins made of
amino acids joined together in a long chain, C, H, O, N, S
how many amino acids are found in proteins
how are amino acids joined together
peptide bonds
what is a dipeptide
protein with two amino acids joined together
what is an oligopeptide
between 10-20 amino acids joined together
what is a polypeptide
longer than oligopeptide, more than 20
what is the simplest amino acid
what is the grouping of amino acids
acidic, basic, polar, non polar, hydrophobic
what are the 2 acidic amino acids
aspartic, glutamic
what are aspartate and glutamate
the ionised form of the acidic amino acids
how do aspartic acid and glutamic acid exist under physiological condition
deprotonated and charged
what is the symbol for aspartic acid
Asp or D
what is the symbol for glutamic acid
Glu, E
what are the 3 basic amino acids
histidine, lysine, arginine
what is the symbol for histidine
His, H
symbol for arginine
Arg, R
symbol for lysine
Lys, K
characteristics o basic amino acids
polar, positively charged below pKa, hydrophilic
what are the non polar amino acids
leucine, proline, mehtionine, tryptophan, isoleucine, phenylalanine, valine, alanine
what are the polar uncharged amino acids
glycine, serene, threonine, cysteine, asparagine, glutamine, tyrosine
what are the 3 aromatic amino acids
phenylalanine, tyrosine, tryptophan
how can we detect the aromatic amino acids
their ability to absorb UV light
what is the primary structure of proteins
order of amino acids occurring in a protein chain
what is the secondary structure of proteins
type of folding, beta sheets or alpha helix
where are beta sheets usually found
inside of protein structures
what is the tertiary structure of proteins
shape of protein when alpha helices and beta sheets coil up and form a 3D structure, interactions of secondary structure with surrounding media
do all proteins possess quaternary structure
no but some proteins do not function without interacting with another identical protein
what is a homodimeric protein and example
2 interacting subunits of the same protein, alcohol dehydrogenase
are nucleic acids used as an energy source
what are nucleic acids made of
C, H, O, N, P
what are 3 functions of nucleic acids?
hereditary material, protein synthesis, energy transporters
all living cells except what contain DNA
mature red blood cells
which organelle has its own circular DNA
what are nucleic acids
polymers of nucleotides
what is a nucleotide composed of
sugar, base, phosphate group
what is the difference in sugar between DNA/RNA
dna-deoxyribose, rna-ribose
what are the pyrimidine bases
c, u, t
how do pyrimidines and purines differ in structure
pyrimidines are composed of single hexagonal ring, purines are double rings
what is a nucleoside
sugar and base
are AMP, ATP, ADP nucleosides or nucleotides
what is Chargaff's Rule
the ratio of A:T is 1:1 and same for G:C
what bonding makes up nucleotides
what bonding holds the strands of DNA double helix together
Hydrogen bonding