Biology CT2 Flashcards
What is the equation for energy transfers?
EJ = mass of water (g) x change in temp x specific heat capacity
what is the specific heat capacity of water?
42000
What is the calorimitery?
The process of measuring the amount of heat released or absorbed during a chemical reaction
Steps to the calormetry test?
-Add water - around 20cm(cubed) - to a boiling tube clamped in a retort stand.
-Record the starting temperature
-Place food sample on mounted needle
-Ignite the food sample using a bunsen burner under the boiling tube of water until completely burned - it may be nessasary to relight the food sample
-Record the final temperature of the water
-Record results in a table
-Calculate the change in temp caused by the burning food sample
-Repeat steps 1-8 with this food type to increase reliablity
What is the role of the active site of an enzyme?
The role of the active site is to compliment the substrate molecule.
Why is no starch detected at 150 sec and glucose is detected?
The starch has been fully broken down into simple sugars
Why the time taken for the milk to curdle decreases from 30 to 40?
The enzymes are becoming denatured so their active sites will not compliment the milk as well so it would decrease the time to curdle.
What is the steps for the practical for testing starch?
- ass iodine to spotting tile
- add amylase + buffer to a test tube, mix then add starch solution, start stopwatch
- After 20-30 sec, add a drop of solution to iodine in spotting tile.
define osmosis?
water molecules diffuse from an area of high concentration to low concentration through a partially permeable membrane until in equilibrium, resulting in a net
define net
the actual amount of molecules that have moved
What happens in osmosis in animals when there is high concentration outside the cell
water enters cell due to it having a lower concentration. the cell will then potentially burst due to it sewelling
What happens in osmosis in animals when there is a high concentration in the cell
water leaves the cell. the cell will then shrivel and crenate
what happens in osmosis in plants when there is high concentration outside the plant cell
Water enters the plant cell via cytoplasm & vacuole. The Vacuole & cytoplasm swell and push against cell membrane. It then pushes and stretches the cell wall. The cell becomes turgid (swells)
what happens in osmosis in plants when there is high concentration inside the plant cell
Water leaves the plant causing the cell to contract (shrink). The cell shrinks, becomes flaccid and the cell membrane pulls away from the cell wall causing the cell to become plasmolysed.
define flaccid
floppy
if someone inherits a disorder what would their coding be
BB or bb
define homozygous
the same alleles
define heterozygous
different alleles
define phenotype
a characteristic we inherited that we can see. e.g. eye colour
define genotype
something we inherit that we can not see. e.g. Bb
steps for the osmosis practical
- set up 4/5 boiling tubes, each with sucrose solution
- prepare 4/5 potato cylinders using a borer and cut them to the same length. Dry them using a paper towel to remove liquid and record the mass before placing it into one of the boiling tubes
- Leave them for 30/40 mins
- remove the potato, remove excess liquid from the surface of the cylinder with a paper towel. and record the mass.
- repeat the practical
what is the independent variable of the osmosis practical
concentration of sucrose in the solution
what is the dependent variable of the osmosis practical
the change in mass of the potato cylinders
How many blood groups are there
4
what are the blood groups
A, B, AB, O
What type of blood type is O
recessive blood type - homozygous
What type of blood type is AB
codominant- both alleles are expressed
What type of blood type is B and A
both dominant alleles
what are the blood type A genotypes?
/A /O or /A /A
what are the blood type B genotypes?
/B /O or /B /B
what are the blood type AB genotypes?
/A /B
what is the RH+/- system (rhesus)
Red blood cells sometimes have another antigen, a protein known as the RhD antigen. If it is present you are RhD + if not you are RhD
how many years are between ‘Ardi’ and ‘Lucy’
1.2 million
What are Darwin’s four main ideas / laws
-Variation
-Heredity
-Struggle for existence
-Natural selection
what does codominant mean
both alleles are expressed AB
define natural selection
only the survivors of the competition for recourses will reproduce.
define mutation
a change in a gene that creates a new allele
what causes a genetic variation
the different alleles inherited during sexual reproduction
define acquired characteristics
characteristics that are changed by the environment during the life of the individual
define discontinuous variation
where the data can only take a limited set of values
define continuous variation
where the data can be any value in a range
define evolution
a gradual change in the characteristics of a species over time
define how scientists used stone tools to get the age of the rock
they assume that a stone tool is the same age as that layer of rock
how are stone tools made?
-by hitting it
-with another stone
-to knock flakes/chips off
