Stephanie'sChapter5

Chapter 5 Continuity in Cells __ Cell Structure (5.1-5.6 p107-119) __ Cell theory – the idea that cells are the basic unit of life; this idea came about in the 1700s and 1800 · 1)Cells, or products made by cells, are the units of structure and function all organisms   · 2) All cells come from pre-existing cells Prokaryotes – an organic whose cells do not have membrane-enclosed organelles, such as nuclei, mitochondria, and chloroplasts; a bacterium

Eukaryotes – an organism whose cells have a membrane-enclosed nucleus and organelles; a protest, fungus, plant, or animal

Organelles – membrane-enclosed structure in eukaryotes
 * Organelles Only in Plants || [[image:plantcell.png width="334" height="253"]] ||
 * [[image:cellwallfigure1.jpg]] || Cell walls: formed by living plants; made of cellulose fibres embedded in a matrix of protein and polysaccharides; provides rigidity to plant cells and allows for development of turgor pressure ||
 * [[image:chloroplast.gif width="452" height="375"]] || Chloroplast: enclosed by a double membrance; third membrance system forms thylakoids in which light-absorbing pigments are embedded. All reactions of photosynthesis occur in chloroplasts ||
 * [[image:vacuole2005.jpg]] || Vacuole: varies in size; larger vesicle enclosed in single membrane; may occupy more than 50% of the volume in a plant cell ; contains water and digestive enzymes; stories nutrients and waste products

Contain enzymes, store nutrients and waste product, regulates the water content of the cell ||


 * Organelles only found in animal cells || [[image:animalcell.png width="411" height="288"]] ||
 * [[image:25lysosome.png width="349" height="194"]] || Lysosome: site of intracellular digestion; formed by budding from Golgi apparatus ; fuses with vesicles containing food particles ingested by cell

It is an enzyme that helps break down large molecules and worn out cell parts. ||
 * [[image:spindals.jpg]] || Centrioles: tubular structures formed of microtubules; occurs in pairs during interphase; duplicate prior to mitosis and form organizing centers for mitotic spindles in protist and animals

OR (easier)

- A pair of cylindrical structures that play an important role in cell division ||


 * Organelles in both Plant and Animals Cells ||
 * [[image:plasma.gif]] || Plasma Membrance: Encloses the cell’s membrane it has two tin lipid layers that controls the passing of material in and out of the cell. ||
 * [[image:nucleus.jpg width="282" height="258"]] || Nucleus: contains most of cell’s genetic information in DNA ||
 * [[image:cytoskeleton.jpg width="368" height="205"]] || Cytoskeleton: network of proteins of hollow microtubules ||
 * [[image:Mitochondriafigure1.jpg width="258" height="275"]] || Mitochondrion: enclosed in double membrance; inner membrance is folded most of the cells respirations happens here; contains some DNA and RNA; there may be several hundred of these per cell

Help to release energy form food and help in the synthesis of building blocks for large molecules ||
 * [[image:endoplasmicreticulumfigure1.jpg width="335" height="231"]] || Endoplasmic Reticulum (ER): tubular membrane system that helps in the synthesis and transport of lipids and membranes proteins. Rough ER is studded with **ribosomes**, smooth lacks ribosomes

Ribosomes – where proteins are manufactured ||
 * [[image:goli.jpg width="295" height="285"]] || Golgi apparatus: a system of flattened sacs that modifies macromolecules in vesicles for secretion or for delivery to other organelles

Helps to package cells products for export from the cell ||

Nuclear envelope – the membrane in eukaryotes that encloses the genetic material, separating it from the cytoplasm Genes –the hereditary information that control center of the cell Chromosomes – long strands of nucleotides wrapped around protein molecules; these are only visible in nuclear division __ Cell Function (5.6-5.8 p118-p123) __ Metabolism – sum of all the chemical reactions in a cell or organism Diffusion – the movement of a substance down its concentration gradient from a more concentrated area to a less concentrated one

Osmosis – diffusion of liquids such as water through membrane · If the concentration of water molecules is lower in the solution then in the cell, water diffuses out of the cell causing it to shrink · If the concentration of water molecules is greater outside a cell the what in ward and if it is an animal cell it will burst a plant cell will not Passive transport – no energy is expended by the cell, by moving down a concentration gradient Active transport – energy in the form of ATP is used to moves substance through the transport proteins. __ Cell Reproduction (5.9-5.11 p125-p131) __ Cell Cycle

Interphase – a normal interval between successive cell division when the only evidence of future division is that the chromosomes begin to be replicated