Kerboodle Revision Flashcards
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Nucleus
Controls all of the activities of the cell, and surrounded by a nuclear membrane. It contains genes and chromosomes which carry instructions for making new cells or new organisms
Cytoplasm
A liquid gel where most of the chemical reactions needed for life take place
Cell membrane
Controls the passage of substances such as glucose and mineral ions into the cell.
Mitochondria
Where aerobic respiration takes place, releasing energy for the cell.
Ribosomes
Where protein synthesis takes place.
Chloroplasts
Contain green substances called chlorophyll, which absorbs light so plants can make food via photosynthesis.
Root cells do not have chloroplasts because they are underground.
Permanent vacuole
Is a space in the cytoplasm filled with cell sap. Important for keeping the cells rigid to support the plant
Eukaryotic cells
Eukaryotic cells all have a cell membrane, cytoplasm and genetic material that is enclosed in a nucleus. Genetic material is a chemical called DNA
Examples of eukaryotic cells are plants, animals, fungi and protista
Prokaryotes
Prokaryotes, like bacteria consist of cytoplasm and a cell membrane surrounded in a cell wall. The genetic material is not in a distinct nucleus. It forms a single DNA loop.
Nerve cells
Are specialised to carry electrical impulses around the body.
Nerve cell adaptions
Lots of dendrites to make connections to other nerve cells
An axon that carries the nerve impulses from one place to another
The nerve endings, or synapses are adapted to pass the impulses to another cell or between a nerve cell and a muscle in the body using special transmitter chemicals. Mitochondria
Muscle cells specialisation
So that they can contract and relax. Muscle cells work together in tissues. Contain special proteins. Contain many mitochondria to transfer energy. They can store glycogen
Sperm cells
Contain genetic information from the male parent.
Sperm cell adaptions
A long tail which helps the sperm move through the water or the female reproductive system
Middle section full of mitochondria, which transfers energy
Acrosome stores digestive enzymes for breaking down the outer layers of the egg
Large nucleus contain genetic info
Root hair cells
Help take up water and mineral ions more efficiently
They greatly increase their surface area available for water to move into the cell
They have a large permanent vacuole that speeds up the movement of water by osmosis
They have many mitochondria that transfer the energy needed for the active transport of mineral ions.
Photo synthetic cells
Plants can make their own food via photosynthetic cells.
Contain chloroplasts which trap light needed for photosynthesis
Large permanent vacuole which helps keep the cell rigid as a result of osmosis
Usually positioned in layers of the stem of a plant so they can absorb as much light as possible.
Xylem cells
Xylem is the transport tissue in plants that carries water and mineral ions from the roots to the highest leaves and shoots. Xylem is also important for supporting the plant
Xylem cells adaptions
Xylem cells eventually die and form long hollow tubes that allow water and mineral ions to move easily through them.
Also make them strong.
Phloem cells
Is the specialised transport tissue that carries food made by photosynthesis around the plant.
The cell walls between the cells break down to form special sieve plates which allow water carrying disolved food to move freely up and down the tubes when needed
Diffusion
Is the spreading out of particles of any substance, in solution or a gas, resulting in a net movement from an area of higher concentration to lower. Down the concentration gradient
Rate of diffusion is affected by
The difference in concentrations
The temperature
And the available surface area.
A dilute solution
A dilute solution of sugar contains a high concentration of water (the solvent). It has a low concentration of of sugar (the solute)
A concentrated solution
Sugar solution has relatively low concentration of water and high concentration of sugar
Osmosis
The movement of water from a dilute to a more concentrated solute solution, through a partially permeable membrane, that allows water to pass through.
Cell isotonic to solution
When the concentration of solutes in the solution outside the cell is the SAME as the concentration of solutes inside the cell
Cell to hypotonic solution
When the concentration of solutes in the solution outside is LOWER than the concentration of solutes inside the cell
Cell hypertonic to solution
When the concentration of solutes in the solution outside the cell is HIGHER than the concentration of solutes inside the cell
Osmosis in plants
Plant rely on osmosis to support their stems and leaves
Turgor
Turgor pressure makes the cells hard and rigid, which in turn keeps the leaves and stems of the plant rigid and firm
Plasmolysis
If more water is lost by osmosis, the vacuole and cytoplasm shrink, and eventually the cell membrane pulls away from the cell wall. This is plasmolysis
Active transport
Moves substances from a more dilute solution to a more concentrated solution (against the concentration gradient)
Cell cycle stage 1
Replication of DNA to form 2 copies of each chromosome and synthesis of new sub-cellular structures
Cell cycle stage 2
Mitosis, nucleus divides
Cell cycle stage 3
Cell divides in 2
Chromatids
Duplicate chromosome produced during mitosis
Cytokinesis
The dividing of the cell in the last stage of mitosis
Allele
A version of a particular gene
Chromosome
Thread like structure carrying genetic information
Mitosis
Asexual cell division where two identical cells are formed
Differentiations
When cells divide grow and develop causing variation
Organ system path
Cells - tissues - organs - organ systems - organism
Tissue
A group of cells with similar structures and functions
Test for carbohydrates
Iodine turns from red yellow to blue black if starch is present
Test for protein
Blue biuret regent turns purple if protein is present
Test for lipids
Etanol added to a solution gives a cloudy white layer if a lipid is present
How is enzyme activity affected
Temperature and PH
What happens to an enzyme when temperature is too high
It is denatured and stops working
Components of blood
Plasma, red blood cells, white blood cells and platelets
White blood cells
Protect the body from infection
Platelets
Help to clot the blood
Red blood cells
Transports oxygen to cells
Plasma
Transports red blood cells, carbon dioxide and urea
Leaky valves
Heart valves withstand a lot of pressure, and overtime may start to leak or become stiff and not open fully, thus making the heart less efficient.
Artificial pacemakers
An electrical device used to correct irregularities in the heart rate
Artificial hearts
Are occasionally used to keep patients alive while they wait for a transplant.
Transpiration
The loss of water vapour from the surface of plants or leaves
Factors which increase transpiration
Temperature, humidity, air flow and light intensity
Photosynthesis
Water + carbon dioxide ➡️ glucose + oxygen
What affects rate of photosynthesis
Affected by light intensity, temperature, level of carbon dioxide and the amount of chlorophyll
Aerobic respiration
Involves oxygen and glucose long lasting and doesn’t produce lactic acid
Anaerobic respiration
Glucose ➡️ lactic acid (bi product) + energy (short lasting)
Oxygen debt repayment
Lactic acid + oxygen ➡️ carbon dioxide + water
Why is oxygen needed after an anaerobic workout
Oxygen is needed to breakdown the lactic acid that has built up into carbon dioxide and water
The role of the liver
Detoxifying poisonous substances such as ethanol from alcoholic drinks
Breaking down worn out cells and storing it as iron until it is needed to synthesise more blood cells
Metabolism
Is the sum of all of the reactions that take place in a cell or in the body
