2.1.2- Biological Molecules Flashcards
what are polymers?
molecules made from monomers that have joined together
what are monomers?
small units that make up larger molecules
eg-amino acids
what is a condensation reaction
the elimination of water molecule to join monomers by chemical bonds
what is a hydrolysis reaction?
when water is added to a reaction to break a chemical bond between two molecules
what are the 5 properties of water?
-cohesion
-high specific heat capacity
-reactant/metabolite
-good solvent/transport medium
-coolant/high latent heat capicity
what type of molecule is water, and what charges are each atom, with which bonds?
molecule= polar molecule (there is an unequal spread of electrons, so partial changes within the molecule)
atom charge= H+ O-
bonds= hydrogen bonds
what chemical elements make up carbohydrates?
-carbon
-hydrogen
-oxygen
what chemical elements make up lipids?
-carbon
-hydrogen
-oxygen
what chemical elements make up proteins?
-carbon
-hydrogen
-oxygen
-nitrogen
-sulfur
what chemical elements make up nucleic acids?
-carbon
-hydrogen
-oxygen
-nitrogen
-phosphorus
what is a monosaccharide?
a single simple sugar that contains carbon, hydrogen + oxygen in ratio 1:2:1
what is the general formula for a monosaccharide?
Cn (H2O)n
give details on the hexose monosaccharide GLUCOSE
-hexose sugar
-C6H12O6
-energy source, respiratory substrate
-alpha and beta
whats the difference in structure between alpha glucose and beta glucose?
-alpha= OH sticks down
-beta= OH sticks up
what is an example of a pentose monosaccharide?
RIBOSE
what is ribose?
a pentose sugar found in dna, rna + atp
what is the difference between pentose + hexose?
hexose=contains 6 carbons
pentose= contains 5 carbons
what makes up sucrose?
glucose + fructose
what makes up lactose?
glucose + galactose
what makes up maltose?
glucose + glucose
what is a disaccharide?
two monosaccharides bonded together through a condensation reaction (broken by hydrolysis)
what is a polysaccharide?
lots of saccharides joined together
eg-glycogen, starch, cellulose
what bonds appear between saccharides?
glycosidic bonds
what are the two types of starch?
1-amylose
2-amylopectin
—> starch is a mixture of these two
give details on amylose?
-unbranched
-made up of long chains of alpha glucose
-1-4 bonds
-helix shape
give details on amylopectin?
-branched
-1-4/1-6 bonds
what are the 4 functions of starch?
-compact to fit in small space
-readily hydrolysed to produce glucose when needed
-insoluble, so won’t effect water potential of cells
-unreactive/stabilised by hydrogen
what type of substrate is glycogen?
a respiratory substrate that stores energy in animals, eg-glycogen granules in liver/muscle cells
give some details on glycogen?
-made from hundreds of alpha glucose, joined with 1-4 bonds
-branched, compact shape
-can quickly be broken into glucose
what is the role of cellulose?
structural role in plants
give some details on cellulose?
-thousands of beta glucose, 1-4 bonds
-straight, unbranched, arranged in fibres
-every 2nd glucose is rotated 180 degrees
what are the two features of cellulose that help strengthen the cell wall?
-insoluble
-very strong
what are triglycerides made from?
1 glycerol molecule + 3 fatty acids
what is glycerol and what makes it up?
an alcohol molecule, with 3 OH groups
-made from 5 hydrogens, 3 carbons and 3 OH groups
what are fatty acids made up from?
hydrocarbon chain + carboxylic acid group
-hydrocarbon chain can vary in length
what is a saturated fatty acid?
contains single carbon bonds
what is an unsaturated fatty acid?
contains a double carbon bond
how are triglycerides formed?
-glycerol and fatty acids join through condensation, creating ester bonds
what bonds are present in triglycerides?
ester bonds
how are ester bonds broken up?
-through hydrolysis, creating monoglyceride glycerol and one fatty acid
what is triglyceride formation called?
ESTERIFICATION
what are the 7 properties of triglycerides?
-insoluble in water
-poor conductor of heat
-hydrophobic
-high energy content / g
-metabollically inert until hydrolysed
-shock absorbing
-release more water when oxidised in respiration
what are the 5 function of triglycerides?
-energy store, stores energy
-insulation, tissue helps retain heat
-physical protection, cushion delicate organs
-waterproofing, of skin and fur
-metabolic water, water released in respiration
what is cholesterol/what is it made from?
a small narrow, hydrophobic made from 4 carbon based rings.
what is the function of cholesterol and what allows this to take place?
FUNCTION= to make membrane stronger and less fluid
-it can slot between the phospholipids in the membrane due to being small and narrow
what does cholesterol make and what does excess mean?
makes= vitamin D, steroid hormones, to penetrate membranes to reach site of action
excess= gall stones and atherosclerosis.
what are phospholipids made from?
2 fatty acids + phosphate head
-fatty acid tail, phosphate head
what does the phosphate head and fatty acid tail do?
head= hydrophillic, soluble in water
tail= hydrophobic, orientate away from water medium, non-polar
how do phospholipids form bilayers?
their bipolar nature allows molecules to form bilayers, which are a major component of cell membranes.
-in rows
-heads on top/bottom
what are the two functions of phospholipids?
-creates a partially permeable membrane in cells and organelles
-makes up cell membranes
what is the general structure of an amino acid?
amino group = H-N-H
variable group= R-C-H (always different)
carboxyl acid group= OH=C-OH
what are amino acids
the monomer subunit/building blocks of proteins
what are proteins?
polymers of monomer molecules (amino acids)
what bonds are present in proteins?
peptide bonds
what do peptide bonds (in proteins) look like?
O=C—N-H
what are the four levels of the protein structure?
1-PRIMARY structure
2-SECONDARY structure
3-TERTIARY structure
4-QUATERNARY structure
what is primary structure?
chain of amino acids in a polypeptide chain
what is the secondary structure?
the coiling and pleating of parts of the polypeptide chain?
-alpha helix coil
-beta pleated sheet
what one bond is present in the secondary structure of a protein?
hydrogen bonds between amino acids
what is the tertiary structure?
the overall 3D structure of a protein?
what are the 4 bonds present in the tertiary structure?
-hydrogen bonds
-disulfide/covalent bonds of the sulfur ions in the R-group
-ionic bonds (R+—-R-)
-hydrophobic+hydrophillic interactions
what is the quaternary structure?
the overall structure of the protein, including more than one polypeptide chain and an inorganic compound
what is a fibrous protein?
long strands of polypeptide chains that have cross-linkages due to hydrogen bonds, they are generally insoluble in water and typically have structural roles.
what are globular proteins?
A class of spherical shaped proteins that are generally water soluble and typically have metabolic roles.
what are 3 examples of fibrous proteins?
-collagen
-keratin
-elastin
what are 3 examples of globular/conjugated proteins?
-haemoglobin
-insulin (hormone that regulates blood glucose conc)
-catalase (enzyme that catalyses reaction)
give details on haemoglobin?
-a conjugated protein (globular with prosthetic group of iron ions), that transports oxygen in the blood.
-4 polypeptide chains, 2 alpha globin + 2 beta globic
what is the formula and type of ion of SODIUM?
Na+, cation (positively charged)
what is the formula and type of ion of HYDROGEN?
H+, cation
what is the formula and type of ion of CALCIUM?
Ca2+, cation
what is the formula and type of ion of PHOSPHATE?
PO4 3-, anion (negatively charged)
what is the formula and type of ion of HYDROXIDE?
OH-, anion
what is the formula and type of ion of CHLORIDE?
Cl-, anion
what is the formula and type of ion of HYDROGEN CARBONATE?
HCO3-, anion
what is the formula and type of ion of NITRATE?
NO3-, anion
what is the formula and type of ion of AMMONIUM?
NH4+, cation
what is the formula and type of ion of POTASSIUM?
K+, cation
what does SAFES stand for based on globular and fibrous proteins?
Shape
Amino Acid sequence
Function
Examples
Solubility
what is collagen?
an insoluble fibrous protein.
what is the function + properties. of collagen?
-flexible structural protein forming connective tissue
-great tensile strength, due to the many hydrogen bonds within the triple helix structure
-strength, provided by the staggered ends
-stable, due to high proportion of two amino acids (R groups repel)
why is collagen insoluble?
long length, means that it takes ages/too long to dissolve in water
what test is used for proteins?
biuret test
what test is used for reducing/non-reducing sugars?
benedict’s test
what test is used for reducing sugars?
reagent test strip
what test is used for starch?
iodine test
what test is used for lipid?
emulsion test
how do you work out the Rf value when using chromatography?
distance moved by solute / distance moved by solvent.
what is chromatography used for?
to separate the contents within a mixture, separate biological molecules/compounds.
eg- separation of proteins, carbohydrates, vitamins and nucleic acids.
give details on keratin?
-fibrous protein
-present in hair, nails and skin
-sulfur-containing amino acids, so strong disulfide bonds
-strong, flexible and insoluble
give details on elastin?
-fibrous protein in elastic fibres
-present in wall of blood vessels + alveoli
-give structures flexibility to expand when needed but also to return to normal size
-made from stretchy molecule called tropoelastin
