TOPIC+2+CELLS


 * Cells: **http://www.uic.edu/classes/bios/bios100/lecturesf04am/lect06.htm

What else characterizes living things? Metabolism, response, homeostasis, growth reproduction and nutrition – **MR GRaN H**.
 * 2.1 Cell theory (In a nutshell – in anything living actually) **
 * Living organisms are composed of cells
 * Cells are the smallest unit of life
 * Cells come from pre-existing cells.

M = I/A x10 = 1000 ** μ ** m / 100 ** μ ** m Elephants have big ears due to their small **SA: V ratio** Why do mice need to have such a high Metabolism? Why don’t Bacteria need lungs? Multicellular organisms show Emergent properties, Cells in multicellular organisms differentiate to carry out specialized functions by expressing some of their genes but not others. A THERAPEUTIC USE OF STEM CELLS: E.g. Leukaemia: stem cells are obtained from Bone marrow, patients bone marrow cells are killed and replaced with the stem cells
 * Sizes: ** a molecule is 1nm, a cell membrane is 10nm, viruses are abut 100nm, bacteria is about 1 ** μ ** m, organelles up to 10 ** μ ** m, cells up to 100 ** μ ** m
 * Stem Cells retain the capacity to divide and have the ability to differentiate along different pathways. **

** Cell division = Binary fission **
 * 2.2 Prokaryotes: ** The diagram should show the cell wall, plasma membrane, cytoplasm, pili, flagella, ribosomes and nucleoid (region containing naked DNA) learn the functions of each part.

The plant cell wall maintains cell shape, prevents excessive water uptake, and holds the whole plant up against the force of gravity. Animal cells secrete glycoproteins that form the extracellular matrix. This functions in support, adhesion and movement. The diagram should show free ribosomes, rough endoplasmic reticulum (rER), lysosome, Golgi apparatus, mitochondrion and nucleus. The term Golgi apparatus will be used in place of Golgi body, Golgi complex or dictyosome learn the function of each part.
 * 2.3 Eukaryotes **

The diagram should show the phospholipid bilayer, cholesterol, glycoproteins, and integral and peripheral proteins. Use the term plasma membrane, not cell surface membrane, for the membrane surrounding the cytoplasm. whereas **peripheral** proteins are attached to its surface.
 * 2.4 Membranes **
 * Integral ** proteins are embedded in the phospholipid of the membrane,[[image:membrane.png]]

Diffusion, simple diffusion, facilitated diffusion, osmosis, active transport, endocytosis, exocytosis, Learn definitions for all these terms.
 * Vesicles ** how vesicles transport materials within the cells:


 * 2.5 Cell division **

Cells
 * Cell cycle: comprises ** Interphase (G1,S, G2), mitosis, cytokinesis
 * Interphase ** is an active period in the life of a cell when many metabolic reactions occur, including protein synthesis, DNA replication and an increase in the number of mitochondria and/or chloroplasts.
 * Mitosis: PMAT: ** Include supercoiling of chromosomes, attachment of spindle microtubules to centromeres, splitting of centromeres, movement of sister chromosomes to opposite poles, and breakage and re-formation of nuclear membranes. Textbooks vary in the use of the terms chromosome and chromatid. In this course, the two DNA molecules formed by DNA replication are considered to be sister chromatids until the splitting of the centromere at the start of anaphase; after this, they are individual chromosomes.
 * Growth, embryonic development, tissue repair and asexual reproduction involve mitosis. **