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Ch3
Cells
Term | Definition |
---|---|
Cells | Smallest living subunits of a multicellular organism |
Cell/plasma membrane | Only allows certain substances to cross |
Cholesterol | Embedded in the membrane, decreases fluidity stabilizing the membrane |
Proteins | Form antigens when combined with oligosaccharides |
Oligosaccharides | Act as receptor sites for hormones or other compounds |
Nucleus | Contains chromosomes |
Cytoplasm | Liquid solution of dissolved minerals, gases, and other molecules |
Organelles | Organs of the cell |
Ribosomes | Made of protein and rRNA |
Endoplasmic reticulum | Membranous tubules that extends from the nuclear membrane to the cell membrane |
Rough ER | Ribosomes on the surface |
Smooth ER | No ribosomes on the surface |
Golgi apparatus | Flat membranous sacs stacked like pancakes |
Mitochondria | Power house of the cell |
Lysosomes | Contains digestive enzymes called lysozymes |
Centrioles | Organize spindle fibers that separate chromosomes during cell division |
Cytoskeleton | The supporting framework of the cell |
Cilia | Beat in unison causing a wave like motion to move things across the surface |
Flagella | Mobile threadlike projection through the cell membrane |
Microvilli | Folds of the cell membrane that increase surface area |
Vacuoles | Pinched off plasma membrane during phagocytosis and pinocytosis |
Cellular transport mechanisms | Mechanisms to move substances in and out of the cell |
Diffusion | Movement of molecules from an area of greater concentration to an area of lesser concentration along a concentration gradient until equilibrium is reached |
Osmosis | Diffusion of water through a selectively permeable membrane |
Isotonic solution | Equal concentration of solutes |
Hypotonic solution | Lower concentration of solutes |
Hypertonic solution | Higher concentration of solutes |
Facilitated diffusion | Diffusion of molecules through a membrane with help from proteins in the cell membrane called transporters or carrier enzymes |
Filtration | Substances are forced through a membrane by mechanical pressure |
Active transport | Energy requiring process of moving molecules against a concentration gradient |
Phagocytosis | Moving cell engulfs something |
Pinocytosis | Stationary cell engulfs something |
Exocytosis | When a cell releases contents outside the cell |
DNA | Double strand of nucleotides twisted into a double helix made up of Adenine, thymine, guanine, cytosine |
Adenine | Only pairs with thymine |
Guanine | Only pairs with cytosine |
Sequence of A, T, G, C | Determines the genetic code |
Genome | The entire genetic code |
Gene | The genetic code for one protein |
RNA | Similar to DNA except, single-strand, has a U in place of T |
MRNA | Messenger RNA |
TRNA | Transfer RNA |
RRNA | Ribosomal RNA |
Protein synthesis | Occurs in the ribosomes |
Proteins | Chains of amino acids |
Transcription | Messenger RNA is created from instructions on the DNA |
Translation | TRNA attaches to the mRNA at a site on the tRNA called the anticodon which has complementary bases to the codon on the mRNA |
Mitosis and meiosis | Two types of cell division |
Mitosis | One cell divides into two identical cells both having a full set of chromosomes |
Diploid number | Full set of chromosomes |
Stages of mitosis | Interphase, prophase, metaphase, anaphase, telophase |
Interphase | DNA replication |
Prophase | Chromosomes coil up, nuclear membrane disappears, centrioles move to opposite ends and extends spindle fibers to the chromosomes |
Metaphase | Chromosomes line up in the middle, Centromere's attach to the spindle fibers and divide |
Anaphase | Spindle fibers pull chromosomes to each pole |
Telophase | Chromosomes uncoil to become chromatin, nuclear membrane reforms |
Cytokinesis | Cytoplasm divides and cell membrane closes off |
Meiosis | One cell divides into four cells each having half of the chromosomes |
Meiosis in women | Occurs in the ovaries |
Meiosis in men | Occurs in the testes |
Meiosis phases | Same as mitosis but all happens twice except for Interphase |