CELL STRUCTURE & FUNCTION A REVIEW

CELL THEORY 1. All living organisms are made of one or more cells. The cell is the basic organizational unit of life. All cells come from pre-existing cells. 2. 3. Why study cells? them? Haven’t we already learned about • Most diseases/disorders can be explained due to a default at the cellular level.

CELL STRUCTURE OVERVIEW Common Features:  Cell membrane  Nucleus  Cytoplasm

TYPES OF CELLS • Control center of the cell Animal Cells Bacteria Cyanobacteria Plant Cells

GENERALIZED EUKARYOTIC CELL

WHY DIFFERENT? Prokaryotic Eukaryotic (ex. Eukaryotic (ex. animal)

CELL SIZE increases, volume increases much more rapidly. • Most cells are relatively small because as size increases, volume increases much more rapidly. – longer diffusion time

ANIMAL CELLS http://www.sbaran.net/7science/cells/AnimalCellParts.jpg

PLANT CELLS http://www.sbaran.net/7science/cells/PlantCellParts.jpg

COMPLETE THE TABLE Organelle Structure/ Location Function Plant &/or Animal Cell The following organelles should be in the above table: Plasma/cell membrane Cell wall Cytoplasm (cytosol and organelles) Nucleus Nucleoplasm and Nucleolus Rough endoplasmic reticulum Smooth endoplasmic reticulum Golgi bodies/complex Ribosomes Mitochondria Chloroplasts Lysosomes Vacuoles Vesicle

CELL WALL Structure Function Found in plants, as well as some bacteria, protists, and fungi Structure •Thicker, stronger, and more rigid than cell membranes •Capable of supporting large plants •Made up of tiny fibers of cellulose •Perforated with many pores (e.g., tall trees) Function • Protects cell from rupturing • Allows cell to exchange material communicate with other cells with environment and to

CELL WALL

• Nuclear membrane surrounds nucleus • Contains genetic material (DNA) • Directs activities of the cell • Usually single, some cells several, none RBC • Nuclear membrane surrounds nucleus • Nuclear pores – controls the movement molecules in and out of the nucleus – Nucleolus  found inside nucleus  makes ribosomes of

NUCLEUS

ENDOPLASMIC RETICULUM • Transports molecules throughout the cell • Made of membranes that act as channels or passageways

GOLGI APPARATUS (also called Golgi “body”) for transport  Packages proteins and other molecules for transport  Does this by membranes out of the cell surrounding the protein with and puts the proteins in a “vesicle” (tiny vacuole)

ORGANELLES MADE OF JUST A MEMBRANE – Vesicles – transport materials out of the cell or transports and stores materials inside the cell – Lysosomes containing - membrane-bound vesicles digestive enzymes – Vacuoles - contain water and other materials; used for storage  plant cells have usually 1 large vacuole  animal cells have several small vacuoles

Cytoplasm Extracellular fluid Endoplasmic reticulum Phagocytosis Golgi Food vesicle apparatus Lysosomes Transport vesicle Old or damaged organelle Plasma membrane Digestion of phagocytized food particles or cells Breakdown of old organelle Extracellular fluid

RIBOSOMES – Make proteins – Some ribosomes float around in the cytoplasm while others are attached to the endoplasmic reticulum

glucose + oxygen  carbon dioxide + water + energy MITOCHONDRIA • Releases energy from glucose (cellular respiration) glucose + oxygen  carbon dioxide + water + energy • Structure - outer and inner membranes, (folds called cristae) • Have their own DNA

carbon dioxide + water  glucose + oxygen CHLOROPLASTS •Traps energy from the sun to make glucose in photosynthesis: carbon dioxide + water  glucose + oxygen • Grana – closed compartments of stacked membranes •Thylakoids – disc shaped structure – light capturing pigment • Stroma – fluid matrix

CYTOSKELETON cell shape and anchoring organelles microtubules • Network of protein fibers supporting cell shape and anchoring organelles – Actin filaments Microtubules  cell movement – Microtubules  Hollow tubes Intermediate filaments  Facilitate cell movement  Centrioles – barrel shaped  organelles occur in pairs –  help assemble animal cell’s – Intermediate filaments  Stable - don’t break down microtubules Actin

CYTOSKELETON

CYTOPLASM •Includes the cytosol (liquid), organelles and dissolved sugars, etc. within the cell membrane •Every chemical reaction takes place within the cytoplasm

REVIEW GAME How Fast Can You Label the Animal Cell?

REVIEW GAME How About the Plant Cell?