1B- more biological Molecules Flashcards
DNA purpose ?
Store genetic information- instructions to grow and develop
RNA purpose ?
transfers genetic information to the ribosomes
Ribosomes made of
RNA and proteins
Nucleotide
monomers that make up polynucleotides- phosphate group, pentose sugar and nitrogen containing base
Polynucleotide structure
-Nucleotide join via condensation reactions between phosphate of one and pentose sugar of other forming phosphodiester bond
-sugar phosphate backbone
-
phosphodiester bond
bond between pentose sugar and phosphate
DNA structure
1-double helix of 2 twisted anti-parallel polynucleotide strands held by H Bonds between specific complementry nitrogen containing base pairs
2-deoxyribose sugar
3-thymine
4-long polynucleotide strands
RNA structure
1- single polynucleotide strand
2-ribose
3-uracil
4-short polynucleotide stand
AT and CG number of bonds
AT=2
CG=3
direction of strand in DNA
antiparallel
how to form phosphodiester bonds
condensation reations release a water molecule and links together
DNA semi conservative replication
1-DNA Helicase breaks H bonds between complementary bases on 2 polynucleotide strands and double helix unwinds
2-free floating DNA nucleotides are attracted to exposed complementary base pairs on template strand
3-condenation reactions join nucleotides together via phosphodiester bonds catalysed by DNA polymerase. 4- H Bonds between bases on new and template join foaming 2 DNA strands
Purpose of DNA semi conservative replication
ensure genetic continuity between generations of cells
Action of DNA polymerase
- Active site of DNA polymerase complementry to 3 Prime (OH) end of newly forming DNA strand
- 5 to 3 direction on new strand
- DNA polymerase work on template strands in opposite directions due to antiparallel strands
Direction of DNA polymerase
New strand- 5 to 3
Template strand- 3 to 5
3 prime
5 prime
3= OH 5= Pho5phate
Evidence of semi conservative replication- meselson and stahls experiment
1-2 bacteria samples 1 in light nitrogen and 1 in heavy nitrogen broths
2-sample of DNA taken and spun in centrifuge- heavy N at bottom, Light N top
3-Bacteria grown In Heavy N added to light N broth and left DNA to replicate + New DNA spun in centrifuge
4- IF CONSERVATIVE= light and heavy seperated
5-IF SEMI-CONSERVATIVE= New strand of light and old strand of new+ DNA would settle in middle
6-DNA settled in the middle showing DNA had mixture of new and old strand
IF DNA replication was conservative
DNA strands would stay together
ATP properties
1-releases a small amount of manageable energy at a time so no heat energy wasted
2-small, soluble molecule so can be transported around cell
3-easily broken down release energy instantaneously
4-quickly re-synthesised
5-phosphorylate other molecules to make more reactive
6-ATP can’t pass out of the cell so immediate energy supply
ATP Hydrolysis
ATP + H20 –> ADP + Pi
1- ATP Hydrolyase
2-hydrolysis reaction - uses water molecule to break phosphate bond
3- energy released
4- coupled to other energy-requiring reactions
ATP Syntheisis
ADP + Pi–> ATP + H2O
1- ATP Synthase
2- condensation reaction- releases water molecule as phosphate bond forms
3- energy used
ATP Hydrolysis
ATP + H20 –> ADP + Pi
1- ATP Hydrolyase
2-hydrolysis reaction - uses water molecule to break phosphate bond
3- energy released
4- coupled to other energy-requiring reactions in cells so energy isn’t wasted as heat
ATP Syntheisis
ADP + Pi–> ATP + H2O
1- ATP Synthase
2- condensation reaction- releases water molecule as phosphate bond forms
3- energy used
ATP structure
adenine, ribose sugar and 3 phosphate
Properties of water
1- Important metabolite 2- Good solvent 3- high latent heat of vaporisation 4-can buffer temp changes 5-very cohesive
metabolic reaction
chemical reaction in living organisms that keep them alive
Important metabolite
condensation reaction=chemical reaction that releases a H20 molecule when it bonds monomers together
hydrolysis reaction=chemical reaction that uses H2O molecule when it breaks bonds between monomers
Good Solvent
1-water is polar slightly +ve H attracted to -ve ion
and -ve O attracted to +ve ion forming H bonds
2-Ions surrounded by H2O and dissolve
3-organisms can take up useful ionic substances dissolved in water and transfer them around the body
Important metabolite
1-condensation reaction=chemical reaction that releases a H20 molecule when it bonds monomers together
2-hydrolysis reaction=chemical reaction that uses H2O molecule when it breaks bonds between monomers
3-Organisms uses-
Good Solvent
1-water is polar slightly +ve H attracted to -ve ion
and -ve O attracted to +ve ion forming H bonds
2-Ions surrounded by H2O and dissolve
3-organisms uses = can take up useful ionic substances dissolved in water and transfer them around the body
High latent Heat of Vaporisation
1-lots of Heat energy required to break H bonds between H2O for it to evaporate taking heat energy from surface, lowering temperature
2- organisms uses = water loss through evaporation to cool down with little water loss
Can buffer Temperature changes
1- H bonds give water a high specific heat capacity
2-lots of heat energy used to break the H bonds between water for it to evaporate
3- less energy to heat up water
4-organisms uses= don’t experience rapid temp changes so stabilises body temp for enzymes and aquatic environments
Very Cohesive
1- Cohesion= attraction between water molecules due to polarity
2-Organisms uses= helps water flow so good at mass transport
3- high surface tension with air
4- organism uses= evaporation water droplets form
high specific capacity (buffer temp change) def
energy needed to increase the temp of 1 g or water by 1 degree
where do inorganic ions occur
1- solution in cytoplasm
2-body fluids
Iron ions Fe2+ in Hb
- Hb made of for different polypeptide chains in a Quaternary structure
- Fe2+ in centre binds to oxygen and is oxidised to Fe3+
Hydrogen ions H+
H+ conc determines pH that determine enzyme controlled reaction
