Living Organisms
What is respiration?
Chemical reactions in cells that breakdown nutrient molecules and release energy for metabolism
What are cells?
They are the simplest, smallest functional units that show the characteristics of life
What are carrier proteins?
They are membrane transport proteins along with the channel proteins, which transport substances against the concentration gradient.
What are carbohydrates?
organic molecules made up of hydrogen, oxygen and carbon, with the proportion of hydrogen and oxygen present in the ratio 2:1
What is a limiting factor?
any factor that directly affects the rate of a chemical reaction
What is excretion?
Removal of the waste products and substances in excess of requirements
What is a ciliated cell?
A specialised cell that controls the movement of mucus in the trachea and bronchi with small hair-like structures known as cilia
What is osmosis?
the net movement of water particles from a region of higher water potential to a region of lower water potential through a partially permeable membrane (i.e. down a concentration gradient).
What are proteins?
Organic molecules made of hydrogen, carbon, oxygen but may have nitrogen and sulphur
What are stomata?
Minute openings in the epidermal layers of the leaf
What is movement?
Action by an organism or part of an organism causing a change in position or place
What is differentiation?
Process by which a cell becomes specialised for a specific function.
What is active transport?
proteins on cell membrane that move molecules or ions across a membrane during active transport
What is the test for fats? How is it conducted and what are the possible results?
Ethanol Emulsion Test
Take the sample and mix it with equal volumes of ethanol and water followed by shaking. A cloudy white emulsion will form if lipids are present. If lipids are absent, no emulsion will form.
What is the upper epidermis in a plant?
A layer of leaf tissue made of closely packed cells, covered on the outside by cuticle.
What is a Dichotomous key?
Key used to identify and classify organisms by working through a series of paired statements called couplets.
What are neurones?
Specialized cell responsible for the conduction of electrical impulses
What is crenation?
process by which cell shrinks and little spikes appear on the cell membrane
What is denaturation?
A change in the three dimensional structure of an enzyme or any soluble protein caused by heat or chemicals such as acids or alkalis.
What is chlorophyll?
A green pigment that transfers energy from light into energy in chemicals, for the synthesis of carbohydrates.
What are prokaryotes?
Unicellular organisms which have circular DNA, a cell wall of murein, and no nucleus and membrane bound organelles
What is a rough endoplasmic reticulum?
Membrane bound organelle that takes part in protein synthesis and helps in the transportation of the protein to other parts.
What is plasmolysis?
shrinkage of cytoplasm and cell membrane away from the cell wall.
What are enzymes?
Proteins that are involved in all metabolic reactions, where they function as biological catalysts.
What are guard cells?
Cells enclosing the stomata which control the size of the stomata by their turgor pressure