Biology COPY Flashcards
What are the characteristics of living organisms?
They: move, reproduce, sense the surroundings, grow, respire, excrete waste, and need nutrition.
Describe some typical organelles of an animal cell.
The nucleus contains genetic material and controls the cell’s activities.
The cell membrane surrounds the cell and controls what goes in and out.
The cytoplasm is where most chemical reactions take place and contains enzymes.
Describe some typical organelles of a plant cell.
Chloroplasts carry our photosynthesis, and contain chlorophyll.
The cell wall supports the cell and strengthens it and is made of cellulose.
The vacuole contains ell sap and helps to support the cell.
What are tissues and what are organs?
Tissues are similar cells working together to carry out a particular function, for example muscle tissue.
Organs are groups of tissues working together to perform a function.
What makes a plant and what is an example?
Plants are multicellular, with features of a plant cell. They also store carbohydrates as sucrose or starch. Eg. Tomato plant.
What makes an animal, and what is an example?
They are multicellular, and don’t have chloroplasts or cell walls. Often store carbohydrates in the form of glycogen. Eg. cornetfish.
What makes a fungi and what is an example?
These can be single celled. They can have a body of mycelium made up of hyphae. Their cell walls are make of chitin. They have saprotrophic nutrition where they dissolve their food with enzymes and then absorb it. They can store carbohydrates as glycogen. Eg. Yeast.
What makes a protoctist and what is an example?
They are single celled, have a nucleus, and some have chloroplasts. Eg. Amoeba.
What makes bacteria and what is an example?
They are single celled and don’t have a nucleus. Some have chloroplasts. Eg. Thermus.
What makes a virus and what is an example?
They are parasites and depend on living organisms to reproduce. They have a protein coat around some genetic material. Eg. Rabies virus.
What organisms are pathogens and what diseases do they cause?
Protoctists can cause malaria. Bacteria can cause pneumonia, and viruses can cause rabies.
What does an enzyme do and what is it made of?
It is a catalyst, and speeds up useful chemical reactions in organisms. These reactions are called metabolic.
Enzymes are proteins.
What does an enzyme do in a reaction?
It usually breaks up or joins together chemicals, called substrates. The substrate goes into the active site of the specific enzyme and gets reacted.
How does temperature effect enzyme’s work?
The temperature changes the rate of the reaction. There is an optimum temp as it gets hotter the substrate particles have more energy and react faster, but after the optimum temperature the enzyme can denature so the active site changes shape and the enzymes don’t work.
Describe an experiment for how temperature affects enzymes.
Use drops of iodine in a spotting tile and every five seconds drop in a drop from a solution of starch and analyse. When the enzyme has worked the starch will no longer turn blue black. Control the temp by adjusting a water bath around the solution.
How does pH affect enzymes?
It changes the rate of reaction as it changes the shape of the active site and denatures the enzyme as you get further away from the optimum pH.
What is diffusion?
The movement of particles from an area where they are highly concentrated to where they are low concentrated.
What is osmosis?
The movement of water molecules through a partially permeable membrane from a region of higher water concentration to a lower one.
How are plant cells affected by water amount?
When they have lots of water they become turgid and strong. Without lots of water they become flaccid and the plant will wilt.
Describe an experiment for osmosis.
Get some visking tubing and fill it with salt solution. Attach a glass tube at the top. Put it in a beaker of pure water and after a day measure how much water has gone up the glass tube.
What is active transport? Where is it used?
The movement of particles from a low concentration to a high one (against a concentration gradient) using energy released during respiration. Eg. Plants take in minerals from the soil.
What affects 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 the hotter it is.
- Concentration gradient - if it’s large particles will move faster. Doesn’t affect active transport.
What is the structure of carbohydrates?
Contains C, H, and O. Starch and glycogen are long strings of simple sugars.
What is the structure of proteins?
Contains C, N, H, and O. It is made up of long chains of amino acids.