Learning Objectives Flashcards
(32 cards)
Cells - describe levels of organisation in organism.
Organelles, cells, tissues, organs, organ systems
Cells - list the structures of animal and plant cells
Nucleus, mitochondria, ribosomes, cytoplasm, cell membrane and plant specific - vacuole, chloroplasts and cell wall.
Cells - describe function of the nucleus
Contains genetic material within chromosomes, controls cell division and regulates protein synthesis.
Cells - describe the function of mitochondria.
POWERHOUSE OF THE CELL (aerobic respiration).
Cells - describe the function of ribosomes.
Responsible for protein synthesis.
Cells - describe the function of cytoplasm.
Site of many chemical reactions.
Cells - describe the function of the cell membrane.
Made from proteins and a phospholipid. Acts as a p.p.m.
Cells - describe the function of vacuoles.
Bound by the tonoplast - a compartment for excretory molecules. Solute dissolved in sap has low water potential so it can help draw in water from the cytoplasm and therefore outside the cell.
Cells - describe the function of chloroplasts.
Contains chlorophyll, a green pigment which traps sunlight. Associated with photosynthesis.
Cells- describe the function of cell walls.
Made of cellulose. The rigid cell wall prevents the cell from bursting when it takes water in via osmosis and allows it to become turgid. It can also protect the cell from some pathogens
Cells - know the similarities and differences between the structures of plant and animal cells.
Plant cells contain all animal cell organelles (at GCSE) along with a vacuole, cell wall and chloroplasts.
Cells - Explain the importance of cell differentiation in the development of specialised cells.
All specialised cells and organs have been constructed as a result of cell differentiation.
Undifferentiated cells can receive signals to undergo changes.
This allows organisms to develop specialised cells for specific functions.
For example, stem cells can develop into nervous cells to carry electrical signals, allowing muscle movement.
Cells - Understand the advantages and disadvantages of using stem cells in medicine.
Stem cells are unspecialised cells from embryos or specific areas in adults.
Some diseases are caused by premature cell death (degenerative disease). If these cells could be replaced by the patient’s own stem cells, there is no chance of the immune system rejecting the cells and the condition could be overcome.
However, adult stem cells (bone marrow) are multipotent, they can only develop into a small variety of cell. Pluripotent cells, which can develop into almost all cell types, embryonic cells are needed, leading to serious ethical implications. Furthermore, stem cells can develop into tumours once inside the body and can carry pathogens with them or may be rejected by the patient’s immune system.
Food and Bio Mol - identify the chemical elements present in carbohydrates, proteins and lipids.
Carbs - C, H, O
Protein - C, H, O, N, S
Lipids - C, H, O
Food and Bio Mol - Which food types should be present in a balanced diet?
Carbohydrates, proteins, lipids, fibre, water, minerals, vitamins
Food and Bio Mol - Describe an experiment to investigate the energy content in a food sample.
Measure the dry mass of the food. Place 20ml of water into a boiling tube. Measure initial temperature of the water. Spear food with a mounted needle and light it up with a Bunsen flame until it catches fire. Place burning food under tube of water. Keep relighting and doing the same until the food no longer burns. Measure the final temperature. Use the equation: E= 4.2m🔺T.
Food and Bio Mol - Identify sources and describe functions of the components of the diet.(vitamins A,C,D)
Carbohydrates - sweet foods and potatoes, cereals and rice - energy store
Protein - meat, pulses and beans - growth and repair
Lipids - processed food, butter, red meat - adipose tissue, energy store
A (carotene) - carrots, red peppers - vision
C - all fruits, especially citrus - needed for producing collagen
D - UV light - needed for bone health
Fibre - wholegrain food and fruit and veg - needed for healthy intestines
Water - found in most foods - needed to replace water lost by sweating and urination and necessary for many chemical processes in body
Food and Bio Mol - How do energy levels change throughout life?
The more active someone is, the more energy they need. Pregnancy also means more energy is needed for the foetus’ growth. Babies and elderly people need the least energy whilst adolescents need the most.
Food and Bio Mol - Describe the structures of carbohydrates, proteins and lipids.
Starch and glycogen are made from simple sugars, proteins from amino acids and lipids from glycerol and fatty acids.
Food and Bio Mol - What is the Benedict’s test?
Place one spatula or 1cm3 of the food sample if it is liquid in a test tube. Add 1cm3 of water and mix. Add an equal volume of Benedict’s solution. Place in a 95C water bath for five minutes. If the solution turns from blue to red-orange, glucose, fructose or maltose is present.
Food and Bio Mol - What is the iodine test?
Place one spatula or 1cm3 of the food sample if it is liquid on a dish. Place a few drops of iodine solution on the sample. If it turns blue-black, starch is present.
Food and Bio Mol - What is the Biuret test?
Place one spatula or 1cm3 of the food sample if it is liquid in a test tube. Add 1cm3 of water and mix. Add an equal volume of potassium hydroxide solution and two drops of copper sulfate solution and stir for two minutes. If it turns purple, protein is present.
Food and Bio Mol - What is the oil emulsion test?
Place one spatula or 1cm3 of the food sample if it is liquid in a test tube. Add 2cm3 ethanol, cover the end and shake. Allow the contents to settle.
Pour the liquid from the top of the mixture into a test tube half-filled with water.
Cloudy = lipid present. Clear = not.
Enzymes - What is the role of enzymes?
To speed up metabolic reactions in the body by lowering the activation energy without being used up - biological catalyst.
