1. CELLS & TISSUES Chapter 3
Cells vary in size, shape, and function; the shape is closely related to function

2. Composition of Cell Nucleus, Cytoplasm, Cell Mebrane
Cytoplasmic organelles perform specific function, but the nucleus controls the overall activities of the cell

3. Cell Membrane (fluid mosaic)
forms outermost boundary
selectively permeable – controls movement of substances into and out of cells
mainly phospholipids but also includes proteins, & carbohydrates
molecules lipid soluble will pass easily; barrier to water soluble substances
proteins function as receptors or form channels

5. Cytoplasm is the area between nucleus and cell membrane, contains organelles – ***Know functions of each organelle***

6. Nucleus
Enclosed in double layered (pores) nuclear envelope that controls the movement of substances between the nucleus& cytoplasm
Nucleolus is a dense body of protein & RNA that functions in the production of ribosomes
Chromatin is composed of loosely coiled fibers of protein and DNA that condenses into the structures known as chromosomes during cell division

8. Movements through cell membranes
Passive transport – no energy required, substances move from an area of high concentration to low concentration (concentration gradient)
diffusion
- scattering of molecules or ions from high concentration to low concentration
- responsible for the exchange of oxygen and carbon dioxide within the body
- rate of diffusion can be increased by short distance, high concentration of diffusion molecules, low molecular weight, & high temperature
(osmosis animation)
facilitated diffusion – carrier molecules (usually proteins) transport a substance from [high] to [low]

11.   Osmosis – H2O molecules move from [high] to [low] through a selectively permeable membrane –
isotonic – a solution that neither gains or loses H2O, has the same concentration of solutes as the solution with which it is being compared
hypertonic – a solution that gains H2O because it has a higher concentration of solutes than the solution with which it is being compared
hypotonic – a solution that loses H2O because it has a lower concentration of solutes than the solution with which it is being compared

15. urine formation – nephrons of kidney
Filtration – forced – movement of molecules from regions of higher hydrostatic pressure to lower hydrostatic pressure
blood pressure causes filtration of H2O & dissolved substances through porous capillary walls
urine formation – nephrons of kidney

16. Filtration

17. Active Transport – requires energy (ATP) and involves the action of carrier molecules in the cell membrane; moves substance “up the concentration gradient”; from [low] to [high]

18. Permease (pump systems) – protein driven transport systems
Active Transport – requires energy (ATP) and involves the action of carrier molecules in the cell membrane; moves substance “up the concentration gradient”; from [low] to [high]
Permease (pump systems) – protein driven transport systems
Endocytosis – cells take in large molecules from their surrounding
Phagocytosis – large molecules, ex. – white blood cell engulfing bacteria
Pinocytosis – water and small molecules
Exocytosis – cells release materials

20. Sodium Potassium Pump https://www.youtube.com/watch?v=MRKgbwl8vCY

22. http://www.youtube.com/watch?v=1w10R9lv7eQ (endocytosis & exocytosis)

24. DNA & RNA carry genetic information
DNA – double helix, sugar is deoxyribose
adenine (purine) – thymine (pyrimadine)
guanine(purine) – cytosine (pyrimadine)
RNA – Single stranded, sugar is ribose, uracil (pyrimadine) replaces thymine
Gene – a segment of a chromosome that is made up of specific base pairs and codes for proteins

27. Protein Synthesis
transcription – synthesis of RNA using a DNA template
translation – the assembly of amino acids to form a polypeptide chain, in a sequence specified by the order of nucleotide in a molecule of mRNA

29. Cell Reproduction & Heredity
Mitosis – a parent cell divides once to produce two genetically identical daughter cells; daughter cells contain the same number of chromosomes as the parent cell; both are diploid in chromosome number (2n)
Meiosis – a parent cell divides twice to produce four cells (gametes) that contain a haploid (n) number of chromosomes; “male” & “female” gametes fuse at fertilization to produce a zygote (2n)

30. Cell Cycle – Interphase and Mitotic Phase (mitosis & cytokinesis)
Interphase – cell grows and “does its specific job”, chromosomes are replicated (duplicated) during this phase
Mitosis – division of the chromosomes – **Know the phases**
Cytokinesis – division of the cytoplasm

32. Mitosis

33. Meiosis