Biology Flashcards
What are the characteristics of living organisms?
They move, reproduce, sense the surroundings, grow, respire, excrete waste, and need nutrition.
What is a eukaryote, and what is an example?
Any organism with a membrane bound nucleus.
What is a prokaryote, and what is an example?
Single celled organism without a membrane bound nucleus.
Describe the effect of temperature on an enzyme - controlled reaction.
- As kinetic energy of particles increases, enzymes and substrate molecules collide more often, so the rate of reaction increases. -The optimum temperature is when particles are colliding as quickly as possible. - Then the active site changes shape, and the rate of reaction slows. Enzymes ‘denature’.
Define: pulmonary, hepatic and renal.
Lungs, liver, and kidneys.
What is an enzyme, and what does it do?
Enzymes are protein catalysts. They speed up useful chemical reactions in organisms (metabolic reactions).
What makes a plant and what is an example?
Plants are multicellular, cells contains chloroplasts - can photosynthesise, have cellulose cell walls, and store carbohydrates as starch. Tomato plant.
What makes an animal, and what is an example?
Animals are multicellular, cells do not have chloroplasts - cannot photosynthesise, no cell walls, store carbohydrates as glycogen.
What makes a fungi and what is an example?
They can have mycelium made of branching filaments called hyphae. Some are single celled, cannot photosynthesise - use saprotrophic nutrition where they dissolve food with enzymes then absorb it, cell walls made of chitin, store carbohydrates as glycogen. Yeast
What is a bacteria and what is an example?
Bacteria are single celled, have a cell wall, cell membrane, cytoplasm and plasmids, no nucleus but do have DNA. Some can photosynthesise. Pneumococcus causes pneumonia
What makes a virus and what is an example?
Parasites that depend on living organisms to reproduce. Have a protein coat around genetic material (DNA or RNA). Influenza virus causes flu.
What makes a protoctist and what is an example?
Protoctists are single celled, some have chloroplasts. Plasmodium causes malaria.
What organisms are pathogens and what diseases do they cause?
Protoctists can cause malaria, bacteria can cause pneumonia and viruses can cause rabies.
Describe some organelles in a typical plant cell.
Chloroplasts carry out photosynthesis contains chlorophyll. Cell wall made of cellulose is made of cellulose. Large vacuole contains cell sap which supports the cell.
Describe some organelles in a typical animal cell.
The nucleus contains genetic information, controls cell’s activities. Cell membrane surrounds cell controls what goes in and out. Cytoplasm is where chemical reactions take place. Ribosomes are where proteins are made. Mitochondria is where aerobic respiration takes place.
What are tissues and organs?
Tissues are similar cells that work together to carry out a particular function (eg muscle tissue). Organs are groups of tissues, which make up organ systems. Digestive system.
What does an enzyme do in a reaction?
It breaks up or joins together chemicals called substrates. The substrate enters the active site of a specific enzyme and gets reacted.
How does pH affect enzymes?
It changes the rate of reaction, the pH affects the bonds holding the enzyme together. The enzyme denatures the shape of active site the further it is from the optimum pH.
Describe an investigation for how temperature affects enzymes.
Put drops of iodine into spotting tile, and add amalyse ans dtarrch solution???
What is diffusion?
The net movement of particles from an area oh higher concentration to an area of lower concentration.
What is osmosis?
The net movement of water molecules across a partially permeable membrane from an area of higher water concentration to an area of lower water concentration.
How could you investigate diffusion in a non-living system?
Phenolphthalein and sodium hydroxide agar jelly cubes put into a beaker with HCl. Pink phenolphthalein will turn colorless as acid diffuses into it. Can investigate the rate of diffusion by using sized cubes - largest surface area to boule ratio will diffuse fastest.
How could you investigate osmosis in a living system?
Identical potato cylinders into different beakers with different concentrations of sugar solution. Leave. If water is drawn in by osmosis they will grow, if water drawn out they will have shrunk.
How could you investigate osmosis in a non-living system?
Fix Visking tube to the end of a thistle funnel and fill with sugar solution. Put into a beaker of water, and measure where the sugar syrup comes up to in the glass tube . Leave. Measure again. Water should have been drawn up through the tube by osmosis.
What is active transport? Where is it used?
The movement of particles against a concentration gradient (from an area of lower concentration to higher concentration), using the energy released by respiration. E.g. Plants take nutrients from soil.
What factors affect the movement of substances?
- Surface area to volume ratio: movement will happen faster with a large surface area compared to the volume. - Temperature: particles move faster, substances move more in and out of cells faster. - Distance : - Concentration gradient : particles will move faster the larger it is. This doesn’t affect active transport.
