Biology Cheet Sheet

8/8/2019 Biology Cheet Sheet

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Cells- Identify the organelles and their functions

- Rough Endoplasmic Recticulum- Protein synthesis

- Ribosomes- The Golgi Apparatus (Modify and package proteins)

- ***Adaptations for function- Red Blood Cells (no nucleus, biconcave, haemoglobin)

- no nucleus (more space for haemoglobin)- biconcave (increase SA:V ration for diffusion of O2)- haemoglobin (binds to O2 reversibly)

- Xylem Vessels- hollow lumen, no cytoplasm (less resistance to water and dissolved mineral

salts- lignin (high tensile strength, mechanical support, prevent collapse)- pits (lateral movement of dissolved mineral salts during damage)- narrow lumen (increase capillary action by adhesion to walls)

- Root Hair Cells- large vacuole, high conc. of solutes (w.p. gradient, osmosis)- long, narrow extension (increase SA:V for absorption of mineral salts, H2O by

osmosis)- mitochondria (provide energy for active transport of dissolved mineral salts)

- Microbes - viruses, bacteria, fungi- Differences and similarities

- ^Fluid mosaic model- phospholipid bilayer- ability to move laterally

- proteins arranged in random manner- labelling diagram- hydrophilic phosphate head- hydrophobic hydrocarbon tail- extrinsic proteins- intrinsic/integral protein- glycolipid- glycoprotein- cholesterol- microfilament



Osmosis, Diffusion- Define

- Osmosis [DO NOT use diffusion for water]- ***w.p. gradient [water potential (Ψ), then use Ψ]

- use more and less negative w.p.

- partially permeable (not semi permeable)- direction of movement of H2O- Effects:

- Plant / Animal cell- More water: Increased size: turgid / Animal cells burst- Less water: Decreased size: flaccid, plasmolysis / haemolysis- No change

- Êndocytocsis- Phagocytosis (Eating)- Pinocytosis (Drinking by vesicles)

- Êxocytosis - secretion

Feel free to scribble here



Enzymes- Biological catalyst

- Activation energy decreased- Increases rate of reaction- Platform in the form of an active site

- Complementary to the substrate- Aligns to substrate in precise orientation- Specific

- Mode of action- lock & key (Enzyme-substrate complex, complementary)- induced fit

- Înhibition- Competitive- Non-competitive

- ***Affected by:- Temperature

- More kinetic energy- frequency of effective collisions- rate of formation of ES complex- rate of product formed- optimal temperature, denatured- weak bonds in enzyme broken- 3D shape distorted, enzyme denatured, active site no longer complementary- effect on the above crap

- pH- affects hydrogen and ionic bonds

- effect on the above crap- OR- pH affects charges at active site use with caution

- Conc. Substrate- Conc. Enzyme- Label a graph with the plateaus and stuff

- Limiting factors for the A, B, C zones in a plateauing graph- Directly affect rate of reaction if quantity is changed, usually at min. value- Zone A: Free active sites available

- Frequency of effective collisions between E&S- Limiting factor is the conc. of substracts

- Zone B: Less free active sites available- Substrate needs to compete for active sites- Limiting factor still limiting but to lesser extent

- Zone C: No more free active sites- Enzymes saturated- Substrate needs to wait for free active sites- Conc. Enzymes is now the limiting factor



Plant Nutrition- Photosynthesis

- Light dependent/independent stages- Dependent: Light + Chlorophyll + H2O = 2H+ + O- (Photolysis of water)- Also, ADP -> ATP

- Happens in the thylakoid of the chloroplast- Stroma = “cytoplasm” of the chloroplast- Independent: CO2 + H+ = Glucose + O2(Carbon-fixing reaction)- Happens in stroma- Action & absorption spectra- Process, requirements, products, occurrence- Rate of photosynthesis (plateaus as amt. of light increases)

- Note limiting factors, Zone A,B,C- Stomata- Adaptations of the leaf

- Thin- Green

- Minerals required- Factors

- Light- CO2- Temperature



Transport in Plants- Structure & functions

- ***Xylem- hollow lumen, no cytoplasm (less resistance to water and dissolved mineral

salts- lignin (high tensile strength, mechanical support, prevent collapse)

- pits (lateral movement of dissolved mineral salts during damage)- narrow lumen (increase capillary action by adhesion to walls)

- ***Phloem- Presence of sieve plate

- Sieve pores that seal with carbohydrate when damaged- Degenerate protoplasm reduces resistance to the flow of nutrients- Presence of companion cell

- with prominent nucleus- lots of mitochondria- loads and unloads phloem via active transport- controls direction of nutrient flow- communicates with sieve tube via plasmodesmata (pores)

- Mass flow (translocation)- Compare features- Pathways in the roots

- root hair cell adaptations- Apoplast [cohesion and adhesion of water]- Symplast [osmosis via w.p. grad]- Vacuolar- Casparian strip

- blocks the passive flow of materials

- forms a barrier at which the apoplastic flow is forced to pass throughthe selectively permeable plasma membrane into the cytoplasm ratherthan continue along the cell wall

- Mechanism- for xylem vessels- transpiration pull- root pressure- capillary action- into leaves from xylem- pits -> mesophyll cells -> cell wall -> water vapour in intercellular air spaces- diffuses out of leaf through stomata into the atmosphere

- mention “source and sink” concept- Transpiration rate

- Affected by:- temperature- humidity- wind speed



Respiration

- Types- Internal

- Aerobic- Anaerobic

- Yeast- Muscles

- Lactic acid- Oxygen debt

- After exercise- Lactic Acid accumulated during anaerobic respiration- Brought to liver, oxidised to glucose- Glucose stored or used for aerobic respiration later on

- External- Ventilation

- Ribs: protects internal organs- Diaphragm: Muscle that pushes and pulls on the lungs- Intercostal Muscles: Muscles that lift the lungs- Volume and pressure

- Features- Is oxygen required?- Energy produced- Products (ATP -> ADP)- Occurrence- Oxidation of Glucose- ^Graph of oxygen pressure vs Hb saturation with oxygen

- Anatomy- Nasal Cavity- Trachea- Bronchi- Bronchiole- Alveoli (Note *** adaptations for gaseous exchange e.g. diffusion)

- Moisture on inner surface, allows gases to diffuse in solution- Single-celled epithelium, short distance for diffusion (don’t say thin)- Large number of alveoli, large surface area for gaseous exchange- Rich network of blood capillaries, maintains steep diffusion gradient

- Capillaries

- Functions of the above- Smoking

- Chemicals- Tar- Nicotine- Carbon Monoxide

- Harmful effects- Increased heartbeat- Increased production of mucus- High blood pressure

- Consequences- Bronchitis- Emphysema- Lung Cancer



Ecology- Definition

- Producers- Consumers- Trophic Level- Niche

- Pyramids- Number Pyramids- Biomass- Energy

- Loss pathways- As heat due to respiration- Metabolic waste- Unconsumed body parts- Undigested parts of food- For growth, repair, movement- Therefore transfer between trophic levels is inefficient

- Always draw as bars, not a triangle- Carbon Cycle- Effects of man

- Eutrophication (fertiliser runoff)- Nitrogen, phosphorous enters water- Causes algal bloom- Cuts off light, no photosynthesis below surface- Water deprived of oxygen- Animals die, sink to bottom, decompose- CO2 released kills remaining aerobic bacteria

- Bioaccumulation of inert, non-biodegradable toxins (DDT)- Toxins applied, stable toxins remain in the tissues of organisms- Primary consumers feed on producers- Consumers always feed on larger number of lower trophic levels- Toxins accumulate and kills secondary, tertiary consumers, then primary

- Deforestation- Conservation

- Energy Flow



Animal Nutrients- Sources- Functions- Water

- Universal solvent- due to polar nature

- Macronutrients- Fats

- Test in DRY test tube- Energy source

- Carbohydrates- Energy source and storage

- Protein- Growth and repair

- Food tests- Vitamins

- C- D

- Minerals- Fe- Ca

- Balanced diet- Dependence on:- age- gender- activity/metabolism level

- Symptoms of deficiency



Animal Nutrition- Liver

- carbohydrates- insulin- stimulates conversion of excess glucose to glycogen for storage in the liver- glucagon

- alpha and beta cells- islets of Langerhans

- fat- deamination of excess amino acids to ammonia

- urea- kidney

- Hb breakdown to form bile, goes to gall bladder then to duodenum- protein- detoxification

- Processes- ingestion- digestion- absorption- assimilation- egestion

- Anatomy- mouth (buccal cavity)- oesophagus- stomach

- HCl- pepsin

- rennin- mucus- pancreas- duodenum

- Bile (EMULSIFIES does not digest fats)- Amylase- Lipase- Trypsin- SELLEM

- ileum- Adaptations:

- length- surface area- villi- microvilli

- large intestine- rectum- anus



Transport in Mammals- Heart

- Structure (labelling diagrams)- ***Cardiac cycle

- effect of exercise- Initiation (how the nerve cells control the heart)

- Pacemakers- ^Blood Groups

- Blood donations- Coagulation due to surface antigens

- Blood components- RBC- WBC- Platelets

- Blood clotting- Plasma- Functions

- innate and adaptive- Vaccines and antibodies

- Blood vessels- Arteries- Capillaries- Veins- Features and functions

- Coronary Heart disease- causes- effects



Excretion- Structure of the kidney

- Renal corpuscle- Glomerulus- Bowman’s capsule

- Proximal convoluted tubule

- Distal convoluted tubule- Loop of Henle- Collecting Duct- Afferent (in) and Efferent (out) arterioles

- Processes- Ultrafiltration- Selective reabsorption- Urine formation

- ***The annoying essay question- Increase in osmotic pressure (high salt intake, high perspiration, low water intake)- Osmoregulators at hypothalamus- Posterior pituitary gland sends out anti-diuretic hormone- Hormone stimulate DCT and collecting duct to reabsorb more water- Explain stimulus, receptor, messenger, effector in feedback loop- Mention both high and low osmotic pressure

- Dialysis- Haemodialysis- Peritoneal dialysis

Homeostasis- Definition

- Structure of skin- *** Response loop to cold and heat- Reaction of hair- Reaction of capillaries

- Vasoconstriction



Coordination & Response- System

- Reflex Arc- Brain- Nerves

- Sensory

- Intermediate- Motor

- Eye- Eye defects- Structure & Function

- Ciliary muscles- Suspensory ligaments- Radial muscles- Rod and cone photoreceptors

- ***Pupil reflex- ***Accommodation (focusing to distance)

- Hormones- Insulin & glycogen- Adrenaline



Plant Reproduction- ^Vegetative propagation

- rhizome- tuber- runner- bulb

- Parts of a flower- Anther- Stigma

- Pollination- Self vs cross-pollination- Wind vs animal propagation

- ***Fertilisation- ^Seed

- structure- germination & its factors- dispersal mechanisms

- Wind- Animal



DNA & Genetic Engineering- Structure

- DNA- Nucleotide- Antiparallel- Double stranded helix

- Sugar-phosphate backbone (deoxyribose)- Organic bases ATCG- Complementary base pairing- hydrogen bonds between bases

- RNA- Strands- U instead of T- Ribose instead of deoxyribose- Occurrence- Base ration

- Compare- Protein Synthesis

- Transcription- Translation- Functions

- mRNA- tRNA- Ribosome

- Restriction enzymes- *** Steps to genetically engineer a bacteria- Pros and Cons of GE

- Fermenters- Împlications



Genetics- Cross Diagram format

- Note:- List bold items in order- Crosses- Circle the gametes- Arrows or lines from gametes to offspring genotype- Phenotype ratio after listing offspring phenotype

- Phenotype ratios- Both heterozygous:

- Blood Type- A: IA IA / IA IO

- B: IB IB / IB IO

- AB: IA IB (Co-dominance)- O: IO IO

- Genetic crosses- Monohybrid- Sex-linked- Multiple alleles

- Variations- Mutation

- Gene- Type

- Chromosome- Number- Single- Set

- Structure- Artificial Selection- Natural Selection

- Examples- Steps- Selected for and against- Favourable traits or alleles, not genes

Biology Cheet Sheet

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