biochemical Flashcards
define monomer
a small molecules, many of which can be joined tgt to form a polymer
name the monomer and polymer of carbohydrate, proteins and nucleic acid
carbohydrate: monosaccharide, polysaccharide
protein: amino acid, polypeptides and proteins
nucleic acids: nucleotides, DNA or RNA
define condensation
methods which joins small molecules tgt to form larger ones
definee hydrolysis
method which splits larger molecules up into smaller ones
what are the elements in carbohydrate
carbon, hydrogen and oxygen
examples of carbohydrates and their uses
glucose- energy sources released during respiration
starch- energy stored in plants
cellulose- structural building blocks for cell wall
explain monosaccharides and give examples (and where they are found)
simple sugars which are soluble in water.
examples are glucose(end products of digestion), galactose(found in milk) and fructose(found in honey and fruits)
explain disaccharides and give examples
soluble in water, 2 molecules of monosaccharides, can be broken down by hydrolysis
example: maltose(starch partially digested) , lactose(found in milk) and fructose(sugar cane,storage roots)
explain polysaccharides and give examples
complex sugar, not rlly soluble
examples: starch, glycogen(storage for animals, kept in muscles tissues and liver cells) and cellulose
why is polysaccharides a good storage
they are not rlly soluble
name the 4 elements in protein
carbon, hydrogen, oxygen and nitrogen
2 reasons why proteins are essential in our lives
they provide raw materials for building blocks in growth and repairing of tissues; used to make antibodies and enzyme
proteins are made of what subunits
amino acid
_____are made up of amino acid chains
peptides
polypeptides are made of?
a few peptide forming a large complex molecule
how are amino acids joined tgt?
by condensations and peptide bonds
how are the peptide bond broken down?
by hydrolysis and the addition of water molecules
2 amino acids joined tgt are known as a?
dipeptide
true or false: the shape of the protein molecules does not affect their function
false; the shape directly determines their function
what does a nucleotides consist of? (3)
5 carbon sugar, phosphate grp and nitrogenous base
what are nucleotides joined tgt at and what do they form
phosphate grp to form a chain of nucleic acid
what is a double helix?
2 chains of nucleotides are held tgt by a hydrogen bond between bases. the double strand is twisted to form a double helix
how are the bases paired tgt?
a with t and c with g
usage of lipids (5)
source of energy, storage of energy, components making up cell membranal, insultations to reduce heat lost, protection
does double bonds make it easier or harder to to break down
easier
how is the lipid molecule made
1 glycerol linked to 3 fatty acids
which has more cholesterol? saturated or unsaturated fat?
saturated
what is cholesterol and what is it made up of?
class of lipid; four carbon based rings
why can hormones such as testosterone readily pass through plasma membrane
because it as cholesterol/ lipid nature
important uses for water? (6)
photosynthesis, digestion, makes up plasma in the blood, transport medium in plants, excretion, body temp and metabolic reactions
how does water act as a transport medium for humans?
transport dissolved substances like co2, digested food and hormones in plasma
how is water a transport medium in plants (2)
transport dissolved mineral ions in xylem and transport sugar and amino acid in phloem
how to test for starch?
place iodine in food sample; will turn from brown to black
how to test for sugar
use benedicts solution, heat solution up; turns from blue to brick red
how to test for non reducing sugars?
break it down by using strong acid
how to test for protein
biuret test ( sodium hydroxide and copper sulfate); if protein is presents, purple halo if not remains blue
test for fats
put sample in oil then shake it then dump it in water. if got oil then mixture breaks up into many tiny droplets- emulsification
how to test for vitamin C
vitamin c decolourises in DCPIP solution. the more vitamin c the lesser food sample needed to decolourise DCPIPI and faster solution turns colourless
why shld we not shake solution of vitamin c and DCPIPI?
because it is easily oxidise
