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