biology

• Organelle


  Small part of a cell
• 3 basic sections of a cell

  • Plasma membrane
  • Nucleus
  • Cytoplasm
• Plasma membrane

  Also called the cell membrane
• Nucleus


  Also called the control center
• Cytoplasm

  Jelly-like material inside the cell where most organelles float
• Cytoplasm

  • Facilitates chemical reactions
  • Dissolves solutes like carbohydrates and proteins
  • Adds support and pressure to the cell
• Plasma membrane

  Bilayer of lipids and proteins that allows some materials to pass through selectively
• Nucleus

  Contains DNA which is the instructions for making proteins
• Nucleolus

  Makes ribosomes
• Parts visible in electron microscope image of nucleus

  • Nucleolus
  • Chromatin
• Rough endoplasmic reticulum (ER)

  Transports ribosomes which make proteins
• Smooth endoplasmic reticulum (ER)

  Helps make lipids and break down toxins
• Ribosome

  Gathers amino acids and connects them into proteins (translation)
• Golgi body

  Receives, modifies, sorts and packages proteins into vesicles for export from the cell
• Protein export from cell

  1. Ribosome makes protein

  2. Protein placed in vesicle

  3. Vesicle fuses with cell membrane

  4. Protein released from cell
• Mitochondria


  Also called the powerhouse, makes ATP through cellular respiration
• Cell organelle functions

  1. Nucleolus makes ribosomes

  2. Ribosomes exit nucleus

  3. Ribosomes travel along rough ER and create proteins

  4. Golgi body packages and exports finished proteins
• Mitochondria


  The "powerhouse" of the cell that performs cellular respiration to produce ATP, the energy molecule used by cells
• Mitochondria

  • Has its own DNA and ribosomes, can reproduce and replicate, was likely once a free-living organism according to the endosymbiosis theory
• Endosymbiosis theory

  1. Large predator cell engulfs and retains mitochondria ancestor

  2. Mitochondria ancestor multiplies within predator cell

  3. Predator cell divides, passing on mitochondria to daughter cells

  4. Mitochondria and host cell become dependent on each other over time
• Lysosomes


  Contain powerful digestive enzymes that break down food, destroy pathogens, and recycle old cell components
• Cilia and flagella


  Hair-like or whip-like cellular structures that enable cell movement
• Flagella fertilize egg


  Fertilized egg grows into fetus, then child, then high school student
• Cell wall

  Tough, outer layer found in plant, fungal, and bacterial cells that provides structural support
• Cell walls are made of cellulose, a tough material that is difficult to digest
• Robert Hooke first observed cells by examining cork in 1665
• Chloroplasts

  Organelles in plant cells that contain chlorophyll and perform photosynthesis
• Chloroplasts

  • Thought to have evolved from free-living organisms according to endosymbiosis theory, have their own DNA and ribosomes
• Vacuoles

  Large organelles in plant cells that store food, water, waste, and pigments
• Vacuoles are often the largest part of a plant cell, pushing other organelles to the edges
• Phospholipids have hydrophilic heads (water-loving) and hydrophobic tails (water-hating).