Cellular Organization

1
Cellular Organization
2
Elements and Compounds

• Atom-the basic unit of matter the smallest part
  of an element
• Compound-consists of two or more different types
  of atoms combined in a fixed ratio
• Oxygen (O), carbon (C), and hydrogen (H) atoms
  make up over 90 of an organisms mass

3
Chemical Reactions

• Chemical equation-represents a chemical reaction
• Reactants-substances that are required for a
  chemical reaction written on the left side of a
  chemical equation
• Products-substances that are formed during a
  chemical reaction written on the right side of a
  chemical equation

4
Chemical Reactions of Life

• Photosynthesis
• sunlight
• chlorophyll
• 6 CO2 6 H2O ---gt C6H12O6 6 O2
• Cellular Respiration
• C6H12O6 6 O2 ---gt 6 CO2 6 H2O energy

5
Chemical Reactions of Life

• Photosynthesis
• Reactantscarbon dioxide and water
• Productsglucose and oxygen
• Cellular Respiration
• Reactantsglucose and oxygen
• Productscarbon dioxide, water, and ATP energy

6
Organic Compounds

• Organic compounds-compounds that contain the
  element carbon
• Four main groups of organic compounds found in
  living things
• Carbohydrates
• Lipids
• Proteins
• Nucleic acids

7
Organic Compounds (continued)

• Carbohydrates-include sugars and starches used
  by cells to produce energy make up the cell wall
  of plant cells
• Lipids-include fats and oils used by cells for
  energy (after carbohydrates are used up) make up
  the cell membrane, or plasma membrane, of all
  cells

8
Organic Compounds (continued)

• Proteins-include a variety of substances with a
  variety of functions different kinds of cells
  make different kinds of proteins the cells of
  each individual make different proteins a
  secondary component of the plasma membrane of
  cells made up of chains of amino acids
• Nucleic acids-include DNA and RNA, substances
  found in the nucleus of cells DNA makes up
  genes, the basic units of inheritance RNA is
  involved in protein synthesis by cells

9
Cells

• The basic units of structure and function of
  living things
• The building blocks of all organisms
• Cells are composed of atoms/elements and
  compounds

10
The Cell Theory

• All living things are composed of cells and cell
  products.
• New cells are formed only by the division of
  preexisting cells.

11
Cells vary in size, shape and function.

• Prokaryotic cellsprimitive, simple cells which
  lack a nucleus and most organelles (little
  organs or specialized cell structures) the DNA
  of these cells is not enclosed, so it is just
  mixed in with the cytoplasm bacteria are
  prokaryotic these cells are usually smaller than
  eukaryotic cells
• Eukaryotic cellsmore complex cells which contain
  a nucleus and membrane-bound organelles the DNA
  of these cells is separated from the cytoplasm by
  a nuclear membrane members of all other kingdoms
  are eukaryotic these cells are usually larger
  than prokaryotic cells

12
Major Cell Structures

• Plasma membranesemipermeable (or selectively
  permeable) covering of all cells composed
  primarily of a double layer of fatty molecules
  called phospholipids regulates the passage of
  materials into and out of the cell
• Cytoplasmsolution within a cell composed of
  primarily water with dissolved substances (salt,
  sugar, etc.)
• Cell wallouter covering of plant cells exterior
  to the cell membrane composed of cellulose, a
  carbohydrate material that is undigested by
  humans thick, rigid, supportive

13
Cell Structures

• Nucleusfound only in eukaryotic cells the
  control center of a cell contains DNA
• Nuclear membraneporous covering of the nucleus
  has same chemical composition as the plasma
  membrane keeps DNA separated from the rest of
  the cell
• Nucleolussmaller area within the nucleus that
  contains RNA

14
Major Cell Organelles

• Mitochondriapowerhouses of the cell sites of
  cellular respiration produce ATP energy
• Chloroplastssites of photosynthesis in plant
  cells (and the cells of other producers) contain
  chlorophyll
• These 2 organelles are considered the most
  complex. They have their own DNA and can divide
  to reproduce, much as a cell.

15
Cell Organelles

• Ribosomestiny organelles composed of RNA make
  proteins located within cytoplasm or on rough
  endoplasmic reticulum
• Endoplasmic reticulumsystem of tubes or canals
  passing through the cytoplasm functions in
  intracellular transport of various materials
• Rough ERhas ribosomes attached to it transports
  protein
• Smooth ERdoesnt have ribosomes transports
  other materials (lipids)

16
Cell Organelles (continued)

• Golgi bodiesstacks of flattened sacs process,
  package, and secrete cell-produced substances
• Vacuoleslarge sacs containing liquid (water),
  food, or wastes for temporary storage plant
  cells contain a large central vacuole that holds
  water

17
Cell Organelles (continued)

• Lysosomessmall sacs (vesicles) of enzymes
  function in intracellular digestion not found in
  plant cells
• Centriolesbundles of hollow protein tubes
  (microtubules) involved in cell division not
  found in plant cells

18
Other Cell Structures

• Cytoskeletonnet-like arrangement of protein
  fibers throughout the cytoplasm of cells
  believed to help position and move organelles

19
Plant Cells vs. Animal Cells

• Both are eukaryotic, so they have nuclei
• Plant cells are surrounded by a cell wall (with a
  plasma membrane inside) animal cells do not have
  a cell wall (only a plasma membrane)
• Plant cells have chloroplasts and large central
  vacuoles for holding water animal cells do not
  have these
• Animal cells have centrioles and lysosomes plant
  cells do not have these

20
NUCLEUS
CYTOSKELETON
RIBOSOMES
ROUGH ER
MITOCHONDRION
SMOOTH ER
CENTRIOLES
GOLGI BODY
LYSOSOME
PLASMA MEMBRANE
Fig. 4-20, p.65
21
CENTRAL VACUOLE
CHLOROPLAST
CELL WALL
NUCLEUS
CYTOSKELETON
RIBOSOMES
ROUGH ER
MITOCHONDRION
SMOOTH ER
PLASMODESMA
GOLGI BODY
LYSOSOME-LIKE VESICLE
PLASMA MEMBRANE
Fig. 4-19, p.65