Chemistry + Biology A Level Flashcards
What is Diffusion and when does it happen and stop?
Diffusion is the net movement of partials from an area of higher concentration to an area of lower concentration the molecules move both ways but the net movement will be to the area of lower concentration until the partials are evenly distributed through the liquid or gass.
What is the concentration gradient?
The concentration gradient is the path from an area of higher concentration to an area of lower concentration. Partials diffuse down a concentration gradient.
3 properties of water
Metabolite, hydrolysis + condensation reactions need water. ATP is released via hydrolysis reaction
Strong cohesion between water molecules which means it flows well so can be used for transporting substances eg. Water column moves up the xlyme
Water can Buffer changes in temperature because of its high specific heat capacity so it’s a good habitat.
Water is a good solvent because water is polar.
Water has a high latent heat of vaporisation so animals can use it to cool down
What are the names of 2 electron microscopes?
Scanning electron microscope SEM.
transmission elctron microscope TEM.
What is a species?
A species is a group of similar organisms able to reproduce to give fertile offspring.
Species richness?
A messier of diversity which requires the number of different species in a community the number of indevidual in each species.
What is enthalpy formation ?
Enthalpy change is when one mole of something/X is formed from its elements. All reactants and products are in there standard states and in standard conditions.
C(g) +0² (g) > CO² (g)
What is enthalpy of combustion?
Is the enthalpy change when one mole of something is completely combusted in ixigen. All reactants and products are in these standard forms and conditions
What is taxonomy? And what are things organised into?
Taxonomy is the science of classification, it involves naming organisms and putting them in groups. D domain (Do) K Kingdom (keep) P phylum (ponds) C class (cleen) O order (or) F family (frogs) G genus (get) S species (sick)
What’s a hierarchy?
Groups withing groups that never overlap, largest groups at the top and smallest at the bottom. Used in classification of animals.
What are some different ways of comparing DNA?
Genome sequencing - the dna base sequence of one organism can be compared to the DNA base sequence of another organism.
Comparing an animo acid sequence - related organisms have simalar DNA sequences and so similar amino acid sequences in there proteins.
Immunological comparisons - similar proteins will also bind to the same antibodies.
How does gass exchange work in insects? 🐛🐜🦗
Spiricals Tracheae, oxogen down conc gradient to cells, tracheoles, CO ² down conc grad to Spiricals n realsesed
How would you use a ELISA test to check for HIV?
The test will see if a pacient possess the antibodies to the HIV virus.
- HIV antigen is bound to the bottom of a well in a well plate.
- A sample of the pacients blood plasma, which might contain several different antibodies, is added to the well. If there are any HIV specific antibodies these will bind to the HIV antigen stuck to the bottom of the well. The well is then washed out to remove any unbound antibodies.
- A secondry antibody, that had an enzyme attached to it is added to the well. This will bind to the HIV specific antibody, the primary one, and the well is washed out again to remove any unbundled secondary antibodies and enzymes.
- A solution is added to the well that contains a substrate which will react with the enzyme attached to the secondary antibody and produce a colored product. If the solution changes color it indicated that the person is infected with HIV.
What happens in meiosis?
The dna unravels and replicates so there
What is the bond dna nucleotide between the sugar and the phosphate?
Phophodiester bond
What does DNA helicase do?
It unwinds the two strands of DNA by breaking the bydrogen bonds.
What does DNA polymerase do?
It forms the phophodiester bonds by forming nucleotides after lining up the strands of agencent nucleotides.
Contrast the structures of ATP adenosine triphosphate and a DNA nucleotide?
ATP has ribose as a sugar but DNA has deoxy-ribose.
ATPs bace is always Adenine but DNAs base can be Adenine cytosine thymine or guanine
Why would a student doing a test on two types of bacteria in an agar plate boil the agar?
To kill any bacteria that already existed in the agar. So there is no contamination.
Why would a student doing a test on bacteria growth in agar plates transfer the same volume of liquid culture into each plate?
So that she would be able to compare the results in each plate. To allow comparison
Exopeptidases and Exopeptidases are both involved in the hydrolysis of proteins into amino acids, what else is involved?
Membrain bound dipeptidases.
How does a mutation in a gene result in the production of a non functioning protein receptor.?
Change in DNA base/nucleotide (sequence); 2. Change in amino acid (sequence)/primary structure; 3. Alters (position of) hydrogen/ionic/disulfide bonds; 4. Change in tertiary structure
How is the structure of starch related to its functions?
- Helical/ spiral shape so compact
- Large (molecule)/insoluble so
osmotically inactive - Branched so glucose is (easily)
released for respiration - Large (molecule) so cannot leave
cell/cross cell-surface membrane;
How is the structure of cellulose related to its functions?
1.Made of long, straight/unbranched chains of
β glucose
2.Joined by hydrogen bonding
3.To form (micro/macro)fibrils
Provides rigidity/strength
