1.2 Cell Structure and Functions

• Unicellular


  a type of organism that is made up of a single cell

  
• Multicellular


  organisms composed of many cells

  
• Vacuole


  an organelle that stores food, water, and other materials needed by the cell

  
• Chromosome


  a structure in the nucleus that contains hereditary material
• Meiosis


  A process in cell division during which the number of chromosomes decreases to half the original number by two divisions of the nucleus, which results in the production of sex cells
• Mitosis


  cell division in which the nucleus divides into nuclei containing the same number of chromosomes
• Organism


  Any living thing

  
• Organ system


  group of organs that work together to perform a specific function
• Organ


  a collection of tissues that carry out a specialized function of the body
• Tissue


  group of similar cells that perform a particular function
• Golgi body


  A structure in a cell that receives proteins and other newly formed materials from the endoplasmic reticulum, packages them, and distributes them to other parts of the cell.

  
• Endoplasmic reticulum


  a cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another.

  
• Ribosome


  an organelle that is resposible for making proteins.

  
• Mitochondrion


  bean shaped organelle that releases energy from stored food molecules which supplies energy for the cell

  
• Chloroplast


  a structure in the cells of plants and some other organisms that captures energy from sunlight and uses it to produce food

  
• Nucleus


  organelle that controls all the activities of a cell and contains hereditary material made of proteins and DNA

  
• Organelle


  a tiny cell structure that carries out a specific function within the cell
• Cell wall


  strong wall outside a plant cell's cell membrane that protects the cell and maintains its shape

  
• Cytoplasm


  a jellylike fluid inside the cell in which the organelles are suspended

  
• Cell membrane


  thin, flexible barrier around a cell; regulates what enters and leaves the cell

  
• Cell


  basic unit of all living things

  
• What are organs?

  An organ is a group of different tissues that work together to perform a particular function e.g heart
• What are tissues?

  Groups of cells that are similar in structure and function
• What is the endosymbiotic theory?


  Idea that a chemoorganotrophic bacterium and a cyanobacterium were stably incorporated into another cell type to give rise, respectively, to the mitochondria and chloroplasts of modern-day eukaryotes
• What is the cell theory?

  All living things are made up of cells, cells are the basic units of structure and function in living things, new cells are produced from existing cells
• Similarities between plant and animal cell

  Animal and plant cells have the following in common:

  nucleus, nuclear envelope, nucleolus, cell membrane, Golgi, Rough ER, Smooth ER, mitochondrion, vacuole, ribosomes
• Differences between plant and animal cells

  Plants: Have chloroplasts, have a cell wall, have central vacuoles

  Animals: Have centrioles
• Differences between prokaryotes and eukaryotes

  Eukaryotes have a nucleus and membrane-bound organelles and are plant and animal cells

  Prokaryotes are mostly bacteria and do not have a nucleus or membrane-bound organelles
• Nuclear envelope


  Double membrane perforated with pores that control the flow of materials in and out of the nucleus.
• Centrosomes and Centrioles


  Helps the cell divide
• Cytoskeleton


  A network of long protein strands in the cytosol that helps support and shapes the cell
• Cytoplasm/Cytosol


  A jellylike fluid inside the cell in which the organelles are suspended and holds organelles in place and site for chemical reactions
• Mitochondria


  Powerhouse of the cell, organelle that is the site of ATP (energy) production
• Vacuole


  a space or vesicle within the cytoplasm of a cell, enclosed by a membrane and typically containing fluid and stores materials for cells.
• Lysosome


  An organelle that is membrane bound containing digestive enzymes that breaks down food, waste and damaged cell parts all within the cell.
• Golgi body


  A complex structure of vesicles in a cell that receives proteins and other newly formed materials from the endoplasmic reticulum, packages them, and distributes them to other parts of the cell.
• Vesicle

  Small membrane-bound sac that functions in moving products into, out of, and within a cell.
• Smooth Endoplasmic Reticulum

  An endomembrane system where lipids are synthesized, calcium levels are regulated, and toxic substances are broken down.
• Rough Endoplasmic Reticulum


  System of internal membranes within the cytoplasm. Membranes are rough due to the presence of ribosomes. functions in transport of substances such as proteins within the cytoplasm
• Ribosomes


  Links together amino acids to make proteins and enzymes.