Biological Molecules Flashcards
Definition of a polymer
large complex molecules composed of land chains of monomers
Definition of a monomer
small basic molecular units that can join together to form a polymer
Explain the test for non-reducing sugars ( 2parts)
Part 1- add dilute hydrochloric acid to the sample and then heat in a water bath till boiling, finally to nutralise add sodium hydrocarbonate
Part 2- then carry out the test for reducing sugars
Why is part 1 for the testing of non-reducing sugars needed
to break down the sample into monosaccharides
explain/draw the structure of a fatty acid
1- C double bond O
2-OH
3- R
what bond is formed between a fatty acid and a glycerol molecule
ester bond
What type of reaction is needed when joining a glycerol molecule and a fatty acid
condensation reaction
what is released when a glycerol molecule and a fatty acid to joined together
H2O
Water
properties of triglycerides and explain why
(2 main properties)
1- energy storage -because of the long hydrocarbon tails contains lots of chemical energy
2- insoluble in water- because of the hydrophilic heads and hydrophobic tails
Test for lipids
emulsion test -shake the testing sample with ethanol then poor the solution into water if lipids are present a milky/white ppt will be present
what are the 3 functional groups in an amino acid
Carboxyl group(COOH)
Amine/Amino group(NH2)
R group
structure of an amino acid
R
|
H3N-C-COOH
|
H
explain the 4 structure of proteins
Primary Structure- sequence of amino acids in a polypeptide chain
Secondary Structure- hydrogen bonds form between the amino acids and coil into A-helix or B-pleated sheets
Tertiary Structure- more folding and more hydrogen bonding is used with the addition of ionic bonds, disulfide bridges, final 3D structure is formed
Quaternary Structure- where several different polypeptide chains are bonded/assembled together. proteins final 3D structure
Go into detail about the bonds formed in the tertiary structure of a protein formation
additional hydrogen bonding is formed and ionic bonding is then started,
attraction between positivity and negativity charges parts of the molecule
Disulfide bridges- covalent bonds between sulfur atoms ( strong bonds)
Test for proteins
Biuret test- test need to be alkaline so add drops of sodium hydroxide to the testing sample
then add copper sulfate solution , if proteins are present the solution will turn purple, the test stays blue if its an negative result.
What is formed when a substrate fits into an enzymes active site, and what happens for substrate molecules being joined together and for an enzyme that is catalysing
enzyme - substrate complex which lowers activation energy
1) for substrate molecules joining together - lowers activation anergy because reducing repulsion between molecules so they can bond more easily
OR
2) or an enzyme that is catalysing- fitting into the active site buts a strain on the bonds holding the molecules together so the substrate molecules can break apart more easily.
describe enzyme properties
also what would happen if the tertiary structure is altered
enzyme structures are related to their tertiary structure . this is because only one complementary substrate will fit into the active site. each enzyme has a different tertiary structure so they all have a different active site. so if the substrate is not complementary an enzyme substrate complex wont be formed and the reaction wont be catalysed. if the tertiary structure is altered the shape of the active site will change , so the substrate cant fit and a complex would be formed
what are competitive inhibitors
molecules that have similar shape to substrate molecules , they compete with the substrate molecules to combine to the active site BUT no reaction takes place. substrate concentration need to increase for the rate to increase
Non- Competitive inhibitors
binds to the enzyme AWAY from its active site. which cause the enzyme to change its shape so substrate molecules can no longer bind. increasing substrate concentration will have little to no effect.
what is the function of RNA
transfer the genetic information form the DNA to the ribosomes.
1- How are 2 nucleotides bonded together
2-Through what type of reaction
3- what is the bond formed
1- bonded through the phosphate of one group and the sugar of another ,
2- condensation reaction is needed.
3- ester bonds (phosphodiester bonds)
the chain of phosphates and sugars are knows as what
sugar-phosphate backbone
name 4 ways in which the structure of an RNA molecule differs from a DNA molecule
- ribose sugar
-uracil replaces thymine
-only forms a SINGLE polynucleotide strand
-RNA strands are much shorter
what are the 5 properties of water
1- important metabolite
2- good solvent
3- high latent heat of vaporisation
4- can buffer/resist changes in temperature
5-very cohesive
how is water a
important metabolite?
good solvent ?
has a high latent heat vaporisation ?
can buffer/ resist changes in temperature ?
very cohesive ?
1- it is included in a lot of metabolic reactions , such as condensation reaction and hydrolysis reactions
2- some substances dissolve in it and many reaction stake place in it 3- lots is heat is needed to have water change form a liquid to a gaseous state. this is useful because we can use water water loss through evaporation to cool down w/o losing to much water - this is because when water evaporates it carries AWAY heat energy from the surface allowing the body to lower its temperature
4- hydrogen bonds give water high specific heat capacity- useful because water does not experience rapid temp. changes , help the body maintain constant internal body temperatures
5- cohesive- they stick together because they are polar ,strong cohesion helps water flow which is good for transporting substances , strong cohesion also means that water has a high surface tension when it comes into contact with air which allows some animals to be able to walk on water.
