Living env

• Amino acids


  The individual units that bond together to form a protein (polypeptide)
• Monosaccharides


  The individual units that bond together to form a polysaccharide (such as starch)
• Enzymes


  Protein molecules that catalyze (help) chemical reactions
• The 3-dimensional shape of a molecule is important to its proper functioning
• Bacteria


  • Prokaryotic cells, which lack a nucleus, and other membrane bound organelles
• Nucleus


  Contains DNA in eukaryotic cells
• Chloroplasts


  • Organelles found in autotrophic cells that produce glucose in the process of photosynthesis
• Mitochondria


  • Organelles where aerobic cellular respiration occurs to produce ATP (energy) in cells
• Cell membrane


  A selectively permeable boundary around a cell
• Diffusion


  The movement of molecules from high to low concentration, from crowded to less crowded, across a membrane if the molecules are small and unchanged
• Large surface area


  Allows for a fast rate of diffusion into a cell (e.g. root hairs, villi)
• Active transport


  Membrane proteins use ATP energy to carry materials into and out of a cell
• Receptors in cell membranes


  Attach to specific molecules (like insulin and other hormones)
• Many of the cells inside the human body are differentiated to carry out specific functions. While all cells in an organism have the same DNA, some genes are activated and others inactivated, causing cells and tissues to differentiate
• Mitosis


  Diploid cell dividing into two identical daughter cells
• Cancer involves body cells dividing uncontrollably by mitosis
• Meiosis


  The process of producing gametes (sex cells) which are haploid (monoploid) cells
• Meiosis is one of the factors responsible for producing variation among the gametes produced by an organism
• Reproduction


  New individuals of an existing species are produced through this process
• Asexual reproduction


  Produces offspring that are genetically identical to the parent organism
• Diffusion


  Movement of molecules from high to low concentration, from crowded to less crowded; occurs naturally, no energy required; molecules move down their concentration gradient
• Cell membrane impedance


  Affects the ability of ions or other charged particles to cross the membrane
• Impedance in living environment


  Opposition to the flow of electrical signals or currents within biological tissues or systems
• Active transport


  A type of membrane transport that requires energy (in the form of ATP) to move materials against their concentration gradient.
• Mitosis


  The process of diploid cell division where a single cell divides into two identical daughter cells, each with the same number and kind of chromosomes as the parent cell. The DNA in the chromosomes is exactly copied, so the genetic information is passed on accurately.
• Meiosis


  A type of cell division that produces haploid (monoploid) gametes (sex cells) through two consecutive nuclear divisions, meiosis I and meiosis II.
• Haploid (monoploid) cells


  Cells that contain only one set of chromosomes, as opposed to diploid cells that contain two sets of chromosomes.
• Primary cell


  A diploid cell that undergoes replication to produce two identical diploid cells, each with a complete set of chromosomes, before entering meiosis.
• Gametes


  Sex cells produced through the process of meiosis, containing only half the number of chromosomes as the organism's other cells. In animals, gametes are typically referred to as sperm (male gametes) and eggs (female gametes).
• Asexual reproduction


  Produces offspring that are genetically identical to the parent organism. Involves only one parent and does not require the fusion of gametes.
• Sexual reproduction


  Produces offspring that are genetically unique, as they inherit traits from two different parents. Involves the fusion of gametes (sex cells) to form a zygote, which then develops into a new organism.
• Gametes


  Sex cells that can be either sperm or eggs. They combine during fertilization to form a zygote in sexual reproduction.
• Receptors in cell membranes

  Proteins embedded in the membrane of a cell that bind to specific molecules, triggering a response within the cell.
• Cell membrane impedance


  The opposition that the cell membrane presents to the flow of ions or other charged particles