Embed Size (px)
DESCRIPTION
as level biology
Citation preview
May 21, 2013
As Biology Just in Time Revision
Unit 1
May 21, 2013
Don't Worry if you've never seen the topic!!
May 21, 2013
Practical Questions
- Variables and how to measure- Safety- Repeats- Control
May 21, 2013
Longer Questions
- Check the Command Words- Answer the question (not what you think it says)!- Bullet Points are OK- Make at least 4 points- Use keywords- Don't repeat the question.
May 21, 2013
DNA Structure
May 21, 2013
DNA Replication
1. Helicase unwinds the DNA forming the replication fork.
2. New nucleotides diffuse into the fork and hydrogen bind with their complementary partners
3. DNA Polymerase joins the nucleotides together forming the new sugar phosphate backbone
May 21, 2013
DNA - Conservative / semi-conservative replication
Meselson and Stahl’s experiments involved growing bacteria in culture media containing either heavy nitrogen (15N) or light nitrogen (14N). The DNA was then extracted from the bacteria. The DNA was then analysed:
May 21, 2013
{1 / 2} molecules shown with one light and one heavy strand {1 / 2} molecules shown with two light strands;
May 21, 2013
DNA vs RNA
May 21, 2013
mRNA vs tRNA
May 21, 2013
DNA vs RNA
May 21, 2013
Protein Synthesis
1) Transcription2) Translation
May 21, 2013
Protein Synthesis
1) Transcription2) Translation
May 21, 2013
Protein Synthesis
1) Transcription2) Translation
May 21, 2013
The Genetic Code
May 21, 2013
Double vs Single Circulation
May 21, 2013
Gaseous Exchange - insects
May 21, 2013
Gaseous Exchange - Fish
May 21, 2013
Gaseous Exchange - single celled
organisms
May 21, 2013
Cardiac Cycle
Label this diagram!
May 21, 2013
Cardiac Cycle
On the diagram, draw arrows to show the flow of blood into and through the rightside of the heart during one beat of the heart.
May 21, 2013
1. SAN sends a wave of electrical activity (depolarization) around the walls of the atria.2. A ring of insulating tissue blocks the wave from passing into the ventricles.3. The AVN conducts the wave into the Ventricles slowly, which gives the ventricles time to fill.4. The Purkinje fibres are fast-conducting and take the wave to the apex of the heart first, so the ventricles contract bottom upwards.
May 21, 2013
0 - 0.2s - Atrial Systole The atria contract, atrial pressure rises &blood is pushed from atria --> ventricles
0.2 - 0.3s - Ventricular Systole The ventricles contract, ventricular pressure rises above atrial pressure and the cuspid valves shut; Ventricular pressure rises, but no blood leavesthe heart yet! When ventricular pressure rises above pressure in the arteries the semi-lunar valves open Blood leaves the heart
0.3 - 0.4s - Diastole The ventricles relax. Ventricular pressure falls and when pressure in the arteries > ventricular pressure the semi-lunar valves shut
0.4 - 0.7s - Diastole The entire heart is relaxed. The cuspid valves open (4) and both atria and ventricles fill with blood.
May 21, 2013
Blood Vessels
May 21, 2013
Blood Vessels
May 21, 2013
Blood Clo/ng1. Platelets are activated by substances released by thedamaged artery wall
2. Platelets become “sticky” and form a “platelet plug” on thesurface of the atheroma
3. Platelet plus releases chemicals which activate thromboplastin
4. Thromboplastin initiates the clotting cascade
May 21, 2013
The clotting cascade
May 21, 2013
Plasma Cell Membrane Structure
May 21, 2013
Transport Across membranes
May 21, 2013
Transport Across membranes
Active Transport
May 21, 2013
Transport Across membranes
Active Transport
May 21, 2013
Transport Across membranes
Active Transport
May 21, 2013
Amino Acid Structure
May 21, 2013
May 21, 2013
Protein Structure
May 21, 2013
Protein StructureExplain the importance of the primary structure of an enzyme to its function.
ANSWERS:
1. Primary structure determines 3D folding
2. Types of A.A. / bonds
3. Position of A.A. determines position of bonds
4. Shape / position/ of active site determined by position of A.A.
5. Shape of active site being correct to bind to substrate
May 21, 2013
Proteins
ANSWERS:
May 21, 2013
Enzymesbiological catalyst & activation energy.
May 21, 2013
Fats & OilsTriglycerides are either fats or oils. They are made from the elements C, H & O only.
1 x glycerol 3 x fatty acid
May 21, 2013
hydroxyl group(-OH)
EsterificationA condensation reaction which causes an ester bond to form between the fatty acid and the glycerol
This happens 3 times to join the 3 fatty acids to the glycerol molecule
carboxyl group(-COOH)
May 21, 2013
Saturated triglycerides have noC=C bonds in them.
They form fats.
Unsaturated triglycerides DO have C=C bonds in them.
They form oils.
May 21, 2013
Lipid structures - omega 3 & omega 6
•Describe omega 3.•How is it different to omega 6? •Why are they so named?
May 21, 2013
Made of: Carbon, Hydrogen and Oxygen
Monosaccharides – 1 sugar molecule
Disaccharides – 2 sugar molecules joined
Polysaccharides – many sugar molecules
Carbohydrates - Saccarides
barleysugar cane
milk
May 21, 2013
Spot the difference?!
Carbohydrates - different structures of glucose
May 21, 2013
+a-glucose
Carbohydrates - condensation reactions:
a-glucose
?
maltose
May 21, 2013
May 21, 2013
+
a-glucose
Carbohydrates - hydrolysis reactions:
a-glucose
maltose
May 21, 2013
Carbohydrates - polysaccharides
May 21, 2013
Carbohydrates - starch
a1-4 bonds between 3 glucose molecules.
Made from 2 molecules - Amylose & Amylopectin
Found in Amyloplasts (starch grains) inside plant cells for energy storage
Insoluble, so no osmotic effect in tissues
Amylose has no branches (1-4 GB only), so access to glucose is slow
Amylopectin has some branches (both 1-4 & 1-6 GB)
May 21, 2013
Carbohydrates - starch
Amylose
Unbranched
branched
Amylopectin
• Amylose - coiled structure / compact - ideal for storage!
• Amylopectin - side branches allow enzymes which break down the molecule to get to bonds easily.
Means GLUCOSE CAN BE RELEASED QUICKLY!
May 21, 2013
Carbohydrates - glycogen1. Made from Poly (α Glucose).
2. Found in muscle and liver cells for energy storage
3. Insoluble, so no osmotic effect in issues
4. Lots of branches (i.e. 1-6 GB present), which allows quick access to glucose
5. Compact shape, so good for storage
May 21, 2013
Carbohydrates - cellulose1. Made from Poly (β Glucose).2. Main component of cell walls as it is a very strongstructural molecule3. Insoluble… for obvious reasons!4. Cellulose has no branches (i.e. 1-4 GB only), so adjacent cellulose chains line up close5. Hydrogen bonds form between adjacent chains, creating very strong cellulose fibrils
May 21, 2013
Water structure - as a dipolar molecule
Water molecules are polarH = Positively charged (δ+)O = Negatively charged (δ-)This allows them to form HydrogenBonds with other water molecules. Thisgives water some useful properties;
May 21, 2013
Lungs
May 21, 2013
Reasons for not getting a valid
conclusion- other variables are present or need considering - no information available about other variables
May 21, 2013
Correlation vs
Causal Link
Causation: when a change in one variable is responsible for a change in another variable
Correlation: when a change in one variable is reflected by a change in the other
May 21, 2013
Using the information in the graph...
May 21, 2013
Using the information in the graph ...
May 21, 2013
Using the information in the graph, describe the effect of storage time on the vitamin C content
of the camu-camu fruit.
May 21, 2013
Using the information in the table ...
Using the data in the table, what is the evidence that drug S is safe for people to take
Using the information in the table, describe the effect that temperature has on the permeability of the membranes of the beetroot cells.
May 21, 2013
Genetics
May 21, 2013
Distinguish between the terms allele and gene; homozygous; recessive allele
Pedigree diagrams
May 21, 2013
Drawing Genetic diagramsParentsPhenotype:
ParentsGenotype:
GametesGenotype:
ZygotesGenotype:
ZygotesPhenotype:
May 21, 2013
May 21, 2013
Genetically Inherited Diseases
May 21, 2013
May 21, 2013
May 21, 2013
Genetic Screening
May 21, 2013
Vectors
May 21, 2013
Genetic Screening
May 21, 2013
Multiple choice - don't leave blank!!
Explain
Describe
May 21, 2013
Compare!
May 21, 2013
Describe an experiment questions
• Include all variables (IV, DV, CV)• Include any relevant safety measures• How to maintain DV (e.g. water bath)• Reference to {range / at least 5} of IV • Appropriate controlled variable named • Reference to repeats / replicates• Include equipment / procedures to use• Reference to comparison of volumes
May 21, 2013
(QWC - Spelling of technical terms must be correct and the answer must be organised in a logical sequence)
May 21, 2013
CVD
• Not smoking• Increase exercise• Improvements to diet (e.g. reduce salt, reduce saturated fat, increase fibre)• Maintaining appropriate weight• Reduced alcohol consumption• Reducing stress• Use of medication e.g. statins,
May 21, 2013
CVD
• Not smoking• Increase exercise• Improvements to diet (e.g. reduce salt, reduce saturated fat, increase fibre)• Maintaining appropriate weight• Reduced alcohol consumption• Reducing stress• Use of medication e.g. statins,
May 21, 2013
CVD
May 21, 2013
![Biology-Unit 2 Revision Powerpoint [Autosaved]](https://img.pdfslide.us/doc/110x75/577cdcb11a28ab9e78ab26ed/biology-unit-2-revision-powerpoint-autosaved.jpg)
