Nucleotides- week 1 Flashcards
what’s the difference between a nucleotide and nucleoside
nucleotide has a phosphate group where as a nucleoside doesnt
Identify bonds within ATP that release energy upon hydrolysis, indicating which produce a greater amount of energy.
-hydrolysis of the each Anhydride residue yields about 30kJ/mol
-hydrolysis of each Ester linkage yields about 14kJ/mol
-hydrolysis of ATP releases about 470kj/mol of useful energy
Explain why ATP has a higher energy as ATP than the value of hydrolysing its chemical bonds
The high energy of ATP comes from the two high-energy phosphate bonds.
explain how Co-enzyme-A can be used as a co-factor for both transport and synthesis of fatty acids.
-Coenzyme A carries fatty acids through the oxidation process in the mitochondria and transfers acetyl groups during the elongation process of fatty acid synthesis in the cytosol.
Draw links between the processes of β-oxidation of fatty acids and oxidation of pyruvate to Acetyl Co-A.
Co-A is also used for esterification of fatty acids- they can be bound to Carnitine for transport, if bound they are destined for β-oxidation to make Acetyl- CoA which;
-increases production when glycolysis rates increase
-produced by oxidation of Fatty Acids
what are Co-enzymes- give examples
they are organic – carbon-based – CARRIER molecules, like:
* Electron Carriers (i.e NADH, it carries the electron/H+ for a enzyme) ● Acyl Carriers (like Co-enzyme A carries acyl groups instead)
what are co-factors- give a example
PARTICIPATE in enzymatic reactions like:
DNA Polymerase (DNA replications) uses Mg2+ to stabilise the negatively charged DNA molecule, its more involved with the in the catalysis
*DNA is very -vely charged due to all the phosphate groups around it
What do co-factors & co-enzymes do?
Molecules that help or facilitate certain enzymatic reactions;
What are our source of co-factors/co-enzymes and give examples of each
most co-enzymes and co-factors are vitamins and minerals that only come from your diet, as your body can make them from scratch.
-when talking about Vitamins we are talking about ORGANIC co-factors & co-enzymes
(examples of them are: vitamin B3(niacin)- is a precursor for NAD & Vitamin B5-is a precursor for CoA)
-Minerals are INORGANIC co-factors in our bodies (e.g. Mg2+ which DNA polymerase will use) not all minerals act as only cofactors- e.g. Ca2+ which is also used for teeth and bones
what are the non-genetic functions of nucleotide molecules (5 points)
- Energy currency
- Facilitators of enzymatic reactions (e.g. as co-factors)
- Chemical links to external stimuli (signals)
- Metabolic intermediates
- Transmission of genetic information
Identify actions and structures involved in cellular signalling
Autocrine- a single cell releases a molecule which then gets attached to a different part of the same cell to elicit the response from itself (i.e hormones
Paracrine- essentially the same thing but the signalling is occurring between 2 different cells instead of the same cell
Endocrine- basically paracrine but it enters the circulatory system to get to another cell
what is the difference between endocrine and paracrine cell signalling
its the implication of the secondary system in the signalling molecule- endocrine molecules enter the circulatory system whereas paracrine doesn’t as the signalling happens locally
what are the classic nucleotide signalling molecules
cAMP/Cyclic AMP(adenine monophosphate) & cGMP/Cyclic GMP(Guanine monophosphate)- the nitrogenous bases are very important
Explain how nucleotide molecules can act as signalling factors through acting as a co-stimulatory molecule or through the transfer of a “useable” group.
-they act as intercellular signal transductions- so transferring into cells the effects of hormones(e.g glucagon & adrenaline)
-also act as regulators of ion channels (can be used to initiate vasodilation-where the cell needs more oxygen/ more energy or can initiate apoptosis-cell death)
Identify role of nucleotide molecules as intermediary metabolites and give an example of this
nucleotides can act as reservoirs/ sort of bins to take up waste material or can act of intermediates linking various molecules together
example- purine metabolism
