own notes c,l,p Flashcards
what are carbohydrates?
organic compounds made up of c,h,o–(made up of simple sugars a&B)?
name 4 examples of carbohydrates
glucose, glycogen, starch, cellulose
what are carbohydrates made of
1 c, 2h, 1o
what are 3 uses of carbohydrates
- storage for energy
- source of energy
- structural units
what are the 3 groups of carbohydrates?
monosaccharides
disaccharides
polysaccharides
describe monosaccharides
- simplest single sugars- simplest carbohydrate
-used as a source of energy
-sugars which taste sweet
-soluble in water - same number of c as o
-form white crystalline solids
3 examples of monosaccharides
fructose, galactose, glucose(C6H12O6)
what are monosaccharides are they monomers
monomers of more complex carbohydrates- bond to form disaccharides or polysaccharides
what are the two isomers ( forms) of glucose?
a-glucose and b-glucose
what are 4 types of monosaccharides?
a-glucose, b-glucose, ribose, deoxyribose
what are isomers?
molecules with the same formula, but whose atoms are arranged differently in space eg a-glucose and b-glucose.
what’s a glyosidic bond?
a bond formed between two monosaccharides by a condensation reaction
(ud)what does a-glucose form?
starch and glycogen
(ud) what does b-glucose form?
cellulose
how are disaccharides formed?
when two monosaccharides are joined together a condensation reaction occurs to produce a glyosidic bond
what are the three most common disaccharides
maltose (reducing s), sucrose (non-reducing s) and lactose (reducing s)
how are disaccharides broken into monosaccharides
by a hydrolysis reaction which requires addition of water
what is the -OH group
the hydroxyl group
if both monosaccharides are a-glucose, what bond do they form?
a 1-4 glyosidic bond .
examples of making disaccharides:
a-glucose+a-glucose=…
maltose
examples of making disaccharides:
a-glucose+fructose=…
sucrose
examples of making disaccharides:
a-glucose+b-glucose=…
lactose
examples of making disaccharides:
b-glucose+b-glucose=…
cellobiose
what is ATP
energy currency of a cell
what are polysaccharides?
polymers of monosaccharides, made of many monosaccharides joined together.
3 examples of polysaccharides…
starch, glycogen, cellulose
what are polysaccharides good as ( examples too)
they are good energy stores- glycogen in animals, starch in plants.
how do polysaccharides hold glucose and how is this useful?
hold glucose molecules in chains, so they can easily be snipped off by hydrolysis when required for respiration ( sped up with enzyme)
is amylose( dk what type/ where from) branched or unbranched?
unbranched
is amylopectin and glycogen branched or unbranched?
branched
amylopectin and glycogen are branched, what does this mean for them?
more compact and offer the chance for lots of glucose molecules to be snipped by hydrolysis at the same time when lost of energy is required quickly.
why are polysaccharides less soluble in water than monosaccharides?
due to their size and regions which could hydrogen bond in water are hidden.
what would happen if many glucose molecules did dissolve in the cytoplasm?
the water potential would reduce so excess water would diffuse in, disrupting the normal workings of the cell.
what is the most common polysaccharide
starch
where is cellulose found & describe it.
found in plants, forming cell walls- tough insoluble fibrous substance
what’s a homopolysaccharide ?
polysaccharide made up of one type of monosaccharide
what’s a heteropolysaccharide?
polysaccharide made up of more than one type of monosaccharide
cellulose is a homopolysaccharide, what is it made of?
made up of b-glucose molecules bonded by condensation reactions to form glyosidic bonds
(chains are straight and lie side by side ( dont spiral)
sate key ideas about cellulose
polysaccharide
chains of b-glucose
are straight( don’t spiral)
cellulose^^ what helps the chain from spiralling
every other b glucose molecule is rotated 180 degrees
what does the hydrogen bonding between the rotated b-glucose molecules in each chain do?
gives the chain additional strength, and stops it from spiralling.
cellulose: what enables the hydrogen bonds to be formed between chains
the hydroxyl group on carbon 2
what are lipids made up of
large amounts of carbon and hydrogen and smaller amounts of oxygen.
are lipids insoluble in water? why?
yes as they are not polar
what are lipids made up of (atoms)
large amounts of carbon and hydrogen and smaller amounts of oxygen.
are lipids insoluble in water? why?
yes as they are not polar- they dissolve in alcohol
what are the three most important lipids?
triglycerides, phospholipids, steroids (all macromolecules)
what is a triglyceride made up of?
1 glycerol and 3 fatty acids
state what glycerol has
3 -OH groups
=its an alcohol
what do fatty acids have?
-have a carboxyl group (-COOH)
attached to a hydrocarbon tail
what can the carboxyl group do?
ionise H+ and -COO- group thus an acid
what does a saturated fatty acid have
no c=c bonds
what does an unsaturated fatty acid have
c=c bonds
what does a single c=c bond mean (in terms of name)
its monounsaturated e.g. oleic acid
what does more than one c=c bond mean (in terms of name
its polyunsaturated e.g. linoleic acid
what does having more than one c=c bond do ***
changes the shape of the hydrocarbon chain (gives it a kink)
what does a kink in the hydrocarbon chain do
kink pushes molecules apart making them more fluid , if there are more unsaturated fatty acids, mp is lower.
what reaction forms a triglyceride and what happens
a condensation reaction occurs (h20 produced) between the -COOH group (fatty acid) and the -OH (glycerol)
what is the covalent bond formed between the glycerol and fatty acid called
an ester bond
what are the 5 functions of triglycerides
- energy source
- energy store
- insulation
- buoyancy
5.proctection
how does a triglyceride act as an energy source
broken doen in respiration to release energy & generate ATP . broken into CO2 and H2O
how does a triglyceride act as an energy store
insoluble in water so doesn’t affect water potential
how does a triglyceride act as an insulator
adipose tissue=storage location for lipid/blubber
what type of bond is an ester bond
a covalent bond
how does a triglyceride aid buoyancy
fat is less dense than water so mammals stay afloat
how does a triglyceride act as protection
fat is around delicate organs- shock absorber.
bacteria covered in lipid
what is a phospholipid
same as a triglyceride but 1 fatty acid replaced with a phosphate group
talk about the fatty acids in phospholipids
fatty acids found here have an even number of hydrocarbon chains-commonly 1 saturate and 1 unsaturated
phospholipids: when surrounded by water what does the phosphate group have?
has a negative charge thus polar
phospholipids: are fatty acid tails polar or non polar
non-polar
phospholipids: what property does the head have
hydrophillic
phospholipids: what property does the tail have
hydrophobic
phospholipids: if they are hydrophobic and hydrophilic, they are…
amphipathic
what may phospholipids form on the surface of water
a layer- heads in tails out
or micelles (tiny balls)
what are phospholipids great at forming?
forming membranes around cells and organelles (phospholipid bilayer)
cholesterol is a ______
lipid
state necessary things about cholesterol
-its a steroid alcohol
-not made of glycerol or fatty acids
-consists of 4 carbon based rings or isoprene units
-small and hydrophobic
- can sit in the middle of the hydrophobic bilayer
-regulates the fluidity of the membrane
where is cholesterol made
in the liver of animals
what does stigmasterol have (found in plants)
has a double bond between carbon 22 & 23
what are steroid hormones made of
cholesterol
can steroid hormones pass through the hydrophobic cell memebrane?
yes because small and hydrophobic
where are steroid hormones abundant
in plants
how do you identify lipids and what’s a positive test
emulsion test-white layer on top
what elements are present in lipids
O,H,C
what elements are present in proteins
C,H,O,N,S
what are peptides made of?
made of amino acid molecules joined by peptide bonds
what are the 4 protein structures
primary, secondary, tertiary, quaternary
what are amino acids
monomers of all proteins, all amino acids have the same basic structure
whats a peptide bond
a bond formed when two amino acids are joined by a condensation reaction
what are proteins
large polymers comprised of long chains of amino acids. the properties of proteins give them a variety of functions.
3 functions of proteins:
- form structural components of animals (muscles)
-their tendency to adapt to specific shapes makes proteins important as enzymes, antibodies and some hormones
-membranes have protein constituents that act as carriers and pores for active transport across the membrane and facilitated diffusion.
what does each amino acid contain? (atoms)
C,H,O,N and sometimes Sulfur
how many amino acids are proteinogenic and what does that mean
only 20
proteinogenic=means that they are found in proteins
what does each protein chain of amino acids contain
an amino group (-NH2) at one end and a carboxyl group (-COOH) at the other end.
what are the three groups that amino acids contain?
amino group, R group, carboxyl group
what do almost all amino acids end in
the -ine group
why are some amino acids hydrophobic and some hydrophilic?
the R group can vary by size, charge and polarity
what happens when amino acids are dissolved in water (key= amino acids act as buffers)
when dissolved, the amino group and carboxyl group can dissolve in water- the amino group accepts H= ions (NH2 to NH3+)
the carboxyl group gives up H+ ion so goes from COOH to COO-
what are amino acids joined together by
by covalent bonds called peptide bonds
just like the glyosidic bond and the ester bond, what does making a peptide bond involve
a condensation reaction ( breaking= hydrolysis)
give an example of peptide bonds being broken (hydrolysed)
protease enzymes in the intestine breaking down peptide bonds during digestion.
what are two amino acids joined together called?
a dipeptide
what is it known as when longer chains of amino acids are joined together
a polypeptide
in terms of chains, what might a protein consist of
a single polypeptide chain or more than 1 chain bonded together
what’s a primary structure protein
sequence of amino acids found in a molecule- sequence of amino acids in a protein chain
what’s the secondary structure protein held by (a-helix)
the helix is held by hydrogen bonds between the -NH group of one amino acid and the -CO group of another for places ahead of it in the chain.
secondary structure, what produces a B-pleated sheet
when such chain (zig-zag structure) folds over itself- the hydrogen bonds between the -NH group of one amino acid and the -CO further down the strand hold the sheet together
what is quaternary structure?~~
many proteins are made up of more than one polypeptide chain (held by same types of bonds that hold tertiary structure)
what is the secondary structure primarily held by
hydrogen bonds
what are the 2 types of proteins
fibrous proteins
globular proteins
describe fibrous proteins
-relatively long, thin structure.
Insoluble in water & metabolically inactive, often has a structure within an organism
describe globular proteins
- has molecules of a relatively spherical shape. soluble in water. Often have metabolic roles within the organism
what’s a prosthetic group
a non-protein component that forms a permanent part of a functioning protein molecule
what is the monomer of carbohydrates
monosaccharides
whats the monomer of proteins
amino acids
whats the monomer of nucleic acids
nucleotides
Why is water polar
oxygen pulls the electrons towards it making it slightly negative, this makes H slightly positive
what is cohesion
two or more water molecules attracting each other via hydrogen bonds
what is surface tension
makes a body of water appear as if there is a film on top. layer able to resist force applied so small animals can walk on it.
what will dissolve in water
ions and polar molecules
is ice less dense than water
yes due to structure
talk about waters latent heat of vaporisation
high latent heat of vaporisation- lots of energy needed to break hydrogen bonds
Is water a good solvent
good solvent as water is polar
2 roles of cholesterol in living organisms
- regulates fluidity of phospholipid bilayer
- converted to steroid
what are peptide bonds between(specific)
between an amine group and a carboxyl group of another
what are the 3 roles of proteins
- structural role (muscle/tendon)
2.metabolic role (enzymes) - transport roles (haemoglobin)
what can R groups vary in
size, polarity, charge
-hydrophobic or hydrophilic properties
when is a protein formed
when one or many polypeptide chains fold into a specific shape that allows it to form a specific function
!what is the secondary structure!
the curling or folding of the polypeptide chain into a-helix or b-pleated sheet due to formation of hydrogen bonds
what are the 3 bonds formed in tertiary structures
-hydrogen bonds (form between polar R groups)
-ionic bonds (formed between positively and negatively charged R groups)
-disulphide bridge (form between sulphur atoms in R groups)
!what is the tertiary structure of a protein!
the overall specific 3D shape of a protein. This is determined by interactions between R groups and properties of R groups.
!what is the quaternary structure of a protein!
the specific 3D shape of a protein that is determined by the multiple polypeptide chains and/or the prosthetic group bonded together.
what are the 3 globular proteins and their role
-haemoglobin- transport protein
-insulin-hormones
-pepsin-enzymes
state stuff about haemoglobin
-4 polypeptide chains (x2 a-globin x2 b-globin)
- conjugated protein, has a prosthetic group on each polypeptide chain .
transports o2 (4 molecules)
state stuff about insulin
-a hormone
- maintains blood glucose conc.
soluble in water (hydrophilic R group outside)
- 2 polypeptide chains- one a helix one b pleated- joined by disulphide links
state stuff about pepsin
- catalyses digestion of proteins
-tertiary structure- kept stable by disulphide bonds and hydrogen bonds
what are the 3 fibrous proteins and their function
collagen- forms tendons
keratin- hardens features eg fingernails
elastin-makes tissues stretchy
what is a fibrous protein
very long, strong protein- insoluble, structural role
state stuff about collagen
- provides strength
-found in artery walls to prevent vessels from bursting
-makes tendons allowing skeletons to move
-used to make bone
-has crosslinks- chains can form H bonds with adjacent chains
state stuff about keratin
-hard and strong
-fingernails, horns, hooves
- contains high amount of cysteine- results in disulphide bonds between polypeptide chains
state stuff about elastin
-can stretch and recoil
- cross linking keep molecules together
-fund in lungs- inflate and deflate
- found in bladder
- found in blood vessel walls
3 examples where hydrogen bonds are present in biological molecules??
-cellulose
-tertiary structure protein
-quaternary structure protein
Describe how the concentration of a reducing sugar can be measured using a colorimeter ?
using , standard / known , concentrations (of reducing sugar) ;
heat with , Benedicts (solution) / CuSO4 + NaOH ;
(use of) same volumes of solutions (each time) ;
(use of) excess Benedicts ;
changes to , green / yellow / orange / brown / (brick) red ;
remove precipitate / obtain filtrate ;
calibrate / zero , colorimeter ;
using , a blank / water / unreacted Benedicts ;
use (red) filter ;
reading of , transmission / absorbance ;
more transmission / less absorbance , of filtrate
= more sugar present ; ora
(obtain) calibration curve ;
plotting , transmission / absorbance ,
against (reducing) sugar concentration
state and explain ways in which the glucose molecule is well suited to its function in living organisms
-soluble so can be transported easily around the organism
-small so can diffuse across membranes
-easily broken down and converted into atp
-molecules can join to form disaccharides or polysaccharides
