Cells, Mitosis, Meiosis, Dna

CELLS, MITOSIS, MEIOSIS, DNA

2 types of cells- Prokaryotic-without nucleus, bacteria Eukaryotic- with nucleus like us

Cell=factory Cell has organelles

Nucleus- first observed, (central office) Chromatin (protein and DNA) Directs activities of the cell Changes to chromosomes (thickens) when the cell gets ready to divide

Nucleolus- Produces ribosomes, not always there

2x membrane-fused with pores allows movement of materials

CYTOPLASM-Proteins and macromolecules Ribosomes- protein synthesis (assembly line workers) Endoplasmic reticulum- site of protein synthesis (assembly line) often connected with nuclear envelope. Golgi Apparatus- packaging and shipping Mitochondria- energy supplier of the cell, double membrane contains Enzymes that breaksdown food and releases energy. Inner folds Create a larger surface area. The more the folds the greater the energy Lysosome- recycling center of cell, mostly in animals, enzymes Vacuoles- storage center, mostly water and mostly plants Cytoskeleton-like scaffolding, recently discovered, allows movement Within the cell (inner walls and stairs) Plastids- produce carbohydrates in plants and unicellular autotrophs Chloro-green pigmented Chromo-various other colors- Remind of senescence Plasma Membrane-protective barrier that surrounds the cell (drywall) Cell Wall- in plants made of cellulose (fat) Primary Secondary-in woody plants for strength (bricks) Middle lamela- pectin (polysacharide) keeps cells together (mortar)

MOVEMENT OF MOLECULES

Diffusion- movement of molecules from an area of high concentration to An area of lower concentration. Osmosis- same as above but only with water Osmotic pressure is pressure caused by osmosis like in you kidneys. You would like no pressure

Permeability- The ability of a material to allow a substance to pass through it Selectively permeable- allows only certain molecules through it. Based on charge, size or solubility

Hypertonic-more solute less solution than what it is compared with

Hypotonic-less solute to solution

Isotonic-inside and out are =

Red blood cells are 80% water, what is a bathtub, saltwater?

Turgid- osmosis in plants The process of wilting is called plasmolysis Pickle production

HOMEOSTASIS- tendency to maintain a constant internal environment!

Passive transport- no energy Active Transport- with energy

Endocytosis- movement into a cell Exocytosis- movement out of a cell

Mitosis/Meiosis

Phases in a cell G1 (growth) cell just divided needs to grow to normal size S (synthesis) 92 chromosomes G2 (Grows more) M (mitosis)

{not dividing it is in interphase}

Interphase - 92 chromosomes Prophase – (92 chromosomes) nucleus starts to disappear; start to see chromosomes; centrioles act like magnets Metaphase- chromosomes align at equator; centrioles opposite ends Anaphase – chromosomes separate Telophase – starts to split; nucleus reappears; chromosomes disappear Interphase – cytokinesis = cell division

Meiosis – (mitosis happening again, after interphase - divides again) Instead of having 46 chromosomes in 2 cells there are 23 chromosomes in 4 cells

Cells Repair Themselves Nerve cells do not reproduce All other cells divide Some cells go through double division

Chromosomes 46 in almost every cell in body

Chalone – Protein If it is there the cell will not divide Nervous system = always has chalone

Cancer – cells divide uncontrollably CARCINOGEN- cancer causing agent viruses chemicals raidation treatments for cancer radiation therapy chemotherapy (drugs) gene therapy

tRNA rRNA Transcription Translation Explain parts of cell to a factory Explain the parts of Mitosis to a train

Centriole Kenetechore Kinesin Chromosome Spindle fibers Centromere DNA – tells cells what to do skin cells = make skin cells, etc. DNA for brain is found in skin – but not used

Replication – DNA makes a copy of itself (46 chromosomes into 92) When does this occur? During interphase (synthesis phase)

What happens during Replication? DNA – unwinds (was in double Helix) Splits because of enzymes Splits between Nitrogen bases (rungs)

Process does not go from point A to Point B in order, but happens in a lot of spots at once

Transcription and Translocation Making a copy of information to make protein with in the cell Makes RNA DNA too big to leave nucleus Oxygen makes RNA smaller RNA – Uracil replaces thymine Adenine goes with Uracil Single strand (not a double Helix)

Translation Translating code to make protein 1st type mRNA – messenger RNA goes to ribosome tRNA – Transfer RNA Anticodon (3 nucleotides) need to find match rRNA- Ribosomal RNA where the codes are matched up . mRNA takes the message from the nucleus, where it goes to rRNA on the rough ER. There it waits for tRNA to bring an amino acid, if the tRNA matches with the mRNA a bond will occur and amino acids will be bonded, a long strand of amino acids will eventually make a protein