MAIN POINTS Flashcards
Function of Vacuole, Cytoplasm, Lysosomes, Golgi apparatus
Vacuole: Storage, Waste management
Cytoplasm: Cell shape, Cell growth and replication
Lysosomes: Cellular digestion and waste disposal.
Golgi apparatus: Transport, sorting and modification of both protein and lipid
Characteristics of Monera and Protista
Monera:
Uni-cellular
Prokaryotic
Have Cell Wall
Protista:
Eukaryotic
Uni-Cellular
Aquatic
Theory of spontaneous regeneration
Idea that non-living matter can give rise to living organisms
Pasteur boiled a meat broth in a flask that had a long neck that curved downward, like a goose. The idea was that the bend in the neck prevented falling particles from reaching the broth, while still allowing the free flow of air. The flask remained free of growth for an extended period
Glycolysis
ANEROBIC process (it does not require presence of oxygen and takes place in anaerobic respiration as well as aerobic respiration)
Splits pyruvates
Releases some ATP
NaDH is collected
Krebs Cycle
Inside mitochondrial matrix
Uses oxygen (aerobic process)
Amphibolic Pathway (catabolic and anabolic processes both)
Makes ATP, NaDH
Electron Transport Chain
Electrons are transferred from NaDH and FaDH to protein complexes and electron carriers.
Used to make a proton and chemical gradient
Experiment to see presence of starch in a leaf (3)
The leaf starch test:
1.Put a black paper strip on the leaf
2.Water bath- put the leaf in the test tube with ethanol. (alcohol- it takes the chlorophyll) A candle below. (we heat it up because it enhances the iodine solution step)
3.Iodine solution- this is the starch test
To remove CO2 use Potassium Hydroxide
Aquatic Plant for Oxygen is Hydrilla
What happens during inhalation and exhalation
Inhalation: Intercostal muscles and diaphragm contracts and moves down, Volume of thorax increases, which decreases the pressure.
Exhalation: Intercostal muscles relax, moving the ribs down and in, the diaphragm relaxes and moves up (into a dome shape), the volume of the thorax decreases, and so the pressure increases, thus, air is released.
Concentration gradient in respiration adaptation
Oxygen moves from alveoli to blood stream where particle pressure is lower and carbon dioxide moves from blood to alveoli where particle pressure is higher.
What is hemoglobin and function of vitamins?
Hemoglobin: Facilitates the transport of oxygen in red blood cell
Vitamins: Chemicals that ensure cells function properly
Food tests for Carbs, Protein, Lipids, Glucose
Carbs: Put substance in beaker, add few drops of iodine, if substance turns blue/black there is starch in the solution
Proteins: Add NaOH and CuSO4 to the solution in the beaker, if colour becomes purple protein is present.
Glucose: Heat the beaker containing the substance and add blue benedicts reagent. If the substance turns orange/brown that means glucose is present.
Lipids: A small quantity of alcohol is added to the test solution - the mixture is shaken vigorously. A milky-white emulsion is formed if fats are present.
Function of accessory organs in the digestive system
Liver: Produces Bile
Gal Bladder: Stores Bile
Pancreas: Secretes insulin and glucagon hormones and makes pancreatic juices which regulate blood sugar levels. Bicarbonates are released to neutralise stomach acid.
Function of Bile
1) Emulsification of fat globules
2) Makes the pH of interstine to Alkaline since digestion of carbohydrates and proteins happens in an alkaline medium
Steps of digestion
Ingestion
Digestion
Absorption
Elimination
Order of events of heart pumping blood
Superior and inferior vena cava bring in dexoygenated blood from the body
Goes into right atrium
Through the tricuspid valve goes into right ventricle
Through the pulmonary valve goes into pulmonary artery
Goes into the lungs ( gets oxygenated)
Goes into Left atrium
Left ventricle pumps the blood into the Aorta
Goes into the rest of the body
How are veins, arteries and capillaries adapted to their function?
Capillaries: They have permeable walls so that substances can diffuse in and out
Their walls are only one cells thick which increases the rate of diffusion by decreasing the distance over which it occurs
Veins: The walls are not thick as blood is not carried at a low pressure
They have a big lumen to help blood flow
They have valves to keep blood flowing in the right direction
Arteries: They have thick layers of muscle to make them strong enough to withstand the high pressure at which they carry blood
They have strong elastic fibres to allow them to stretch and spring back
Factors affecting rate of diffusion
Faster rate:
1. Increasing surface area
2. Decreasing the thickness of the diffusion surface
3. Maintaining a concentration gradient
Hypertonic, Hypotonic and Isotonic
Hypertonic: The solution has a higher solute concentration than the cell, causing water to move out of the cell, leading to shrinkage
Hypotonic: The solution has a lower solute concentration than the cell, causing water to move into the cell, leading to swelling or even bursting
Isotonic: The solution has the same solute concentration as the cell, so there is no net water movement, keeping the cell stable
Mendel’s Laws
Law of dominance: Dominant alleles mask the expression of recessive alleles
Law of segregation: Each individual has two alleles for a trait, and only one is passed on to offspring
Law of independent assortment: The inheritance of one pair of genes is independent of the inheritance of another pair
Enzymes in DNA replication
DNA Polymerase: Builds new set of DNA
Helicase: Breaks the hydrogen bond that holds the DNA bases together (spilts the 2 strands)
Primase: Tells the DNA Polymerase where to start building the new DNA set by creating primer
Ligase: Glues DNA fragments together
Transcription
RNA Polymerase:
Enzyme which binds to the DNA where the gene which needs to be copied starts.
Then, it moves along the gene and read the base one by one to make an mRNA strand
Translation
The ribosome and mRNA strand bind together by adding one amino acid at a time
As the ribosomes move along the mRNA, the tRNA goes away and leaves the amino acids behind, and when the process it completed the ribosomes move away so the left behind amino acids can form a protein.
tRNA
Carry the amino acids on the top and the anti-codon on the bottom.
The anti-codon is complimentary to the codon which codes for the amino acid on the top
They carry the correct amino acids in the correct order so the ribosomes chain them together
Cell Interphase
First gap stage: G1–> 1st stage
First stage of the preparatory phase of cell division.
The cell grows in size and the organelles grow in size.
Does not involve DNA replication
S–> Synthesis (of DNA)
The nucleus and the genetic information (DNA) will get duplicated
Centrosome also gets duplicated (organelles which helps in releasing threads used to separate sister chromatids).
G2 phase
Allows cell to grow more and makes more protein and organelles
Prepares the cell for mitosis
M–> Division (Mitosis / Meiosis)
PMAT
Prophase:
Nucleus is still there but starts disappearing
Chromosomes are visible and are condensing (they are thickening and visible)
The chromosomes are connected to the centromere and are referred to as sister chromatids
Metaphase:
Chromosomes line up in the middle of the cell
No nucleus membrane is presen
Anaphase:
Chromosomes move away and move towards the poles of the cells
Spindles (fibres) that help the chromosomes move towards the end
Telephase:
Chromosomes are at the complete opposite ends (poles)
New nuclei are forming on each side to make new cells
Cytokinesis:
Final separation into two cells
The cytoplasm separates forming new cells
Difference between DNA and RNA
Structure: DNA is double-stranded, meaning it’s made up of two separate chains that twist into a double helix. RNA is usually single-stranded.
Function: DNA stores and transfers genetic information, while RNA creates proteins.
Sugars: DNA contains deoxyribose, while RNA contains ribose. Ribose has an extra -OH group compared to deoxyribose.
Bases: DNA contains adenine, thymine, cytosine, and guanine, while RNA contains adenine, uracil, cytosine, and guanine. Uracil differs from thymine because it lacks a methyl group in its ring.
Reflex arc
Sensory receptor, sensory neurone, relay neurone, motor neurone, motor receptor
Hypothalamus
Maintains homeostasis
Regulates temperature, heart rate, blood pressure
Governs emotional behaviours
Secretes hormones that act on pituitary gland
Process of inserting a gene into an organism (3)
1) Restriction enzyme are used to isolate the required gene, leaving it with a short section of unpaired bases
2) Plasmid and isolated gene are joined together using Ligase enzyme
3) Genetically engineered plasmids are inserted into bacteria cells which then reproduce, spreading the recombinant plasmid.
Why is bacteria ideal for genetic engineering
-Share the same genetic code as other organisms
-Ensure accurate protein production
-Have no ethical concerns
-Possess Plasmids which is easy to manipulate for genetic modification
