general bio chapter 4

• cell theory

  • all organisms are made of cells
  • cells are the fundamental unit of life
  • cells come from preexisting cells
• all cells contain

  • DNA/chromosomes
  • cell membrane
  • cytosol (H2O)
  • ribosomes (translation)
• prokaryotic cells

  • contain a cell well
  • smaller cell
  • lack membrane bound organelles
  • circular chromosome
  • binary fission (how they divide)
• eukaryotic cells

  • lack a cell wall (except plants, fungi, & protists)
  • larger cell
  • contains membrane bound organelles
  • chromosome is linear
  • replicates via mitosis(gesmline cells) or meiosis (sex cells)
• DNA polymerase: enzyme that functions in DNA replication
• plasma membrane: a selective barrier that allows sufficient passage of oxygen, nutrients, and waste to service the volume of every cell
• nucleus: holds genetic information
• nuclear envelope: encloses the nucleus, separating it from the cytoplasm
• RNA

  • nucleotide
  • ribose (sugar)
  • phosphate
• the nuclear size of the envelope is lined by the nuclear lamina which is composed of proteins and maintains the shape of the nucleus
• the DNA and proteins of chromosomes together are called chromatin
• the nucleolus is located within the nucleus and is the site of ribosomal RNA synthesis
• ribosomes: location of translation
• cytosol "free ribosomes": stays inside the cell
• endoplasmic reticulum: leave the cell
• exocytosis: leaving the cell
• endocytosis: moving into the cell
• the endomembrane system consists of

  • nuclear envelope
  • endoplasmic reticulum
  • golgi apparatus
  • lysosomes
  • vacuoles
  • plasma membrane
• golgi apparatus: modify, package, and ship proteins
• smooth ER: lacks ribosomes
• rough ER: surface is studded with ribosomes
• functions of smooth ER

  • synthesizes lipids
  • metabolizes carbohydrates
  • detoxiifes drugs and poisons
  • store calcuim ions
• functions of rough ER

  • has bound ribosomes, which secrete glycoproteins (proteins covalently bonded to carbohydrates
  • distributes transport vesicles, secretory proteins, and surrounded by membranes
  • is a membrane factory for the cell
• lysosome: degrades macromolecules

  • acidic pH
  • enzymes that digest
• protein - protease
• nucleic acid - nuclease
• carbohydrates - carbohydrase
• lipid - lipase
• ase = enzyme
• functions of the golgi apparatus

  • modifies products of the ER
  • manufactures certain macromolecules
  • sorts and packages materials into transport vesicles
• add carb to protein -> glycoprotein
• add fat to protein -> lipoprotein
• vacuoles: large vesicles derived from the ER and the golgi apparatus
• food vacuoles: formed by phagocytosis (jeremy allen white)
• contractile vacuoles: found in many freshwater protists, pump excess water out of cells
• central vacuoles: found in many mature plant cells, hold organic compounds and water
• mitochondria: site of cellular respiration, a metabolic process that uses oxygen to generate ATP
• chloroplasts: found in plants and algae, are the sites of photosynthesis
• purine: an aromatic heterocycle composed of carbon and nitrogen
• endosymbiont theory

  • enveloped by a double membrane
  • contain free ribosomes and circular DNA molecules
  • grow and reproduce somewhat independently in cells