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Life Science Ch. 2
Life Science Chapter 2
Term | Definition |
---|---|
carbohydrate | one or more sugar molecules |
cell theory | living things are made of one or more cells; the cell is the smallest unit of life; new cells come from preexisting cells |
lipid | large macromolecule that does not dissolve in water |
nucleic acid | macromolecule that forms when a long chain of nucleotides join together |
macromolecule | substance that forms by joining many small molecules |
protein | long chain of amino acid molecules |
cell membrane | protects the inside of a cell from the environment |
cell wall | stiff structure outside the cell membrane |
chloroplast | membrane-bound organelle that uses light energy and makes food |
cytoplasm | fluid inside a cell that contains salts an other molecules |
cytoskeleton | network of threadlike proteins inside a cell |
nucleus | directs all cell activities and contains DNA |
organelle | membrane-bound cell structure with a specialized function |
active transport | movement of substances through a cell membrane using the cell's energy |
diffusion | movement from an area of higher concentration to an area of lower concentration |
endocytosis | process during which a cell takes in a substance by surrounding it with the cell membrane |
exocytosis | process during which a cell's vesicles release their contents outside the cell wall |
facilitated diffusion | when molecules pass through a cell membrane using transport proteins |
osmosis | diffusion of water molecules only through a membrane |
passive transport | movement of substances through a cell membrane without using energy |
cellular respiration | series of chemical reactions that convert energy in food molecules into ATP |
fermentation | reaction used to obtain energy from food when oxygen levels are low |
glycolysis | process by which glucose is broken down |
photosynthesis | series of reactions that convert light energy, water, and CO2 into glucose and give off oxygen |