A cell is the basic unit of life

• All living things are made up of cells
• New cells arise from old cells

Phospholipid Bilayer- made up of attached proteins

• Polar (charged) head
• Non-polar (not charged) tail
• Head is hydrophilic
• Tail is hydrophobic

• Keep cells intact
• Regulate movement of molecules in an out of the cell
• Selectively permeable

The random movement of molcules from an area of high concentration to an area of low concentration

*Passive transport, movement of small molecules

Diffusion of water across the selectively permeable membrane

*Passive transport of water based on the tonicity of the environment

The environment has the same solute concentration as cells

*No net movement, normal in animal cells

Solute concentration is lower outside the cell than inside

*less water inside the cell than outside

*water moves into the cell to try and dilute it.

Solute concentration is higher outside the cell than inside

*less water outside the cell than inside

*water moves outside the cell

Stores genetic information of a cell

• Contains all the DNA!

Composed of rRNA and proteins that synthesizes proteins

-Found free in the cytoplasm or fused to the wall of the rough E.R.

• Double helix
• Composed of two spirally strands of nucleotides
• Bases held together through hydrogen based bonds-complementary base pairing
• Adenine + Thymine
• Guanine + Cytosine

Process of making a new copy of a chromosome.

New cells are needed because of:

1. Growth
2. Old ones die
3. Repair

1. Enzyme "unzips" and unwinds the DNA- end up with 2 strands
2. Nucleotides in nucleus bond with exposed nucleotides

*End up with the strands that are identical to each other

*Possible mistakes- if they don't get changed mutations occur

A single strand of nucleotides that can double back on itself.

*Nucleotides are composed of 5-carbon sugar and 4 possible nitrogen containing bases

Adenine + Uracil

Guanine + Cytosine

Ribosomal RNA

(rRNA)

Joins proteins to form ribosomes- free floating in the cytoplasm or in the rough E.R.

**SITE OF PROTEIN SYTHESIS

Messenger RNA

(mRNA)

Transfer RNA

(tRNA)

Transfers amino acids found in cytoplasm to the ribsome as the new protein forms

**Specific tRNA to each amino acid

-> the process of transcribing the DNA triplet code (3 nucleotides stand for 1 amino acid)

Formation of a mRNA strand that is complementary to a protein of DNA

*Making a copy of instructions in DNA "blueprint"

**3 nucleotides per amino acid= 64 unique codes!!

Removes introns,

leaves exons

Occurs in the cytoplasm

-Control life expectancy of mRNA

-How long it lasts in cytoplasm

-How easy it is to bind to a ribosome

• Longest part of the cell cycle
• If moving into Mitosis, duplicates and makes 2 copies of chromosomes 
• See 2 sister chromatids, held together by a centromere

• Chromatin coils into chromosomes
• Centrioles- help direct movement of chromosomes to opposite ends of the cell
• Nuclear envelope fragments

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• Centrioles at opposite poles
• Chromosomes line up at the equator

[image]

• Sister chromatids separate and move to opposite poles

[image]

• Cell elongates, daughter nuclei form at the poles, nuclear envelope reappears
• Chromosomes uncoil and form into chromatin

[image]

• Division of the rest of the cell
• Pinches until 2 cells are formed

[image]

2 nuclear divisions, results in 4 daughter cells

**OCCURS IN GONADS TO PRODUCES GAMETES

*First difference

• Homologous chromosomes line up together to form a tetrad (4)

[image]

• Production of sperm
• Meiosis produces 4 viable sperm

• The production of eggs
• Born with all eggs in prophase I
• Produces 1 egg, 2 polar bodies

Egg is fertilized by 1 sperm 

1 in 64 trillion combos.

Trisomy 21

(3 copies of Chromosome 21)

• Causes physical changes, slanted eyes & flat face

Monosomy X

(1 X Chromosome)

• Look female, sex orgens don't mature-secondary sex characteristics don't develop.

XXY

• Sterile, no kids
• Speech and language delays

XXX

• Taller than average
• Speech and reading problems

End of chromosome breaks off 

**Williams Syndrome- Pixie like face, wide mouth, turned up nose

-Heart problems and mental retardation

-Excellent verbal/music skills

ff

Recessive Phenotype

FF

Dominant Phenotype

Ff

Dominant Phenotype

Need 2 copies to be expressed

If you only have 1 copy then you are a carrier, you are able to pass it on but do not express it

Effected by both the genes and the environment 

EX: Skin Color

Heterozygous has an intermediate phenotype between both homozygote

EX: Flowers!!

Two alleles are equally expressed in the heterozygote

EX: Blood Type

Sex-Linked trait

Mostly males have the disorder, given to them by mother

• Single layer of simple cells
• Think and "leaky"=specialized for diffusion
• Found lining blood vessels and alveoli of lungs

• Simples- single layer of cells
• Stratified- multiple layers of cells
• Psudeostratified- looks stratified because the cells vary in length, but really simple in structure

• Squamos- Floor titles
• Cubodial- Dice
• Columnar- Bricks 

• Multiple layers of mulitiple cells
• New cells push to the surface to take the place of cells that have scraped off--SKIN

Single layer of cube shaped cells

Commonly functions in secretion--Kidneys, ovaries, many glands 

Single layer of rectangular pillar cells

• Important where secretion and absorption is important--lining of SMALL INTESTINE 

Appeared to be layers

Extended surface has cilia--lining the respiratory tract

Can change shape from columnar to squamous due to tension

EX: Urinary bladder

• Fibroblasts are enlarged to store lipids
• Energy storage, insulation, and to protect organs 

• Found in the nose, ends of bones and ribs
• Very find collagen fibers

Cells lie within lacunae with in a matrix of elastic and collagen fibers

EX: Outer ear, very flexible 

Lighter than compact bone

found at the end of long bones

Attached to tendons to bones and move body parts through contraction

Function in the voluntary movement of the body

No striation!!!!

Function in involuntary movements with in the body, found in the walls of internal organs and blood vessels 

Branched muscle fibers with ends of cells bound tightly together

**Involuntary movement of heart

Present in the brain and spinal cord

• Function in sensory input, intergration of data and motor output

1. Dendrite- a process that conducts signals to the body of the neuron
2. Cell Body- contains most of the cytoplasm and the nucleus 
3. Axon- conducts nerve impluses away from the cell body

A series of mutations within a cellular DNA that results in the cells forming a tumor

**Chances of getting it increases with age

Telomeres does not signal for cell to undergo programmed death

**Cells virtually immortal

Cancer cells no longer stop diving when they come into contact with other cells 

*Cancer cells need less stimulus to begin cell divisions

Proteins that stimulate cell cycle

**Has potential to become cancer causing gene with mutation 

Produce proteins that inhibit cell cycle

**Mutation no longer stop the cell cycle or repair DNA damage 

A genetic component to some cancers

*Risks of developing breast, lunch, and colon cancer increase when a first degree relative has the cancer

May be mutagens or carcinogens 

Tobacco contains a number of unknown carcinogens

• Usually a carcinoma
• Screening is very important, the earlier the cancer is detected, the better the chance of survival

Remove the growing tumor and some of the surrounding tissue

Most effecting when tumor is benign

• Use of drugs to kill of cancer cells 
• Damage DNA so badly the cell undergoes programmed death
• Normal cells stop diving in unfavorable conditions

Direct, powerful beams of radiation to areas where we expect to see cancer cells

• 2 Nasal cavaties
• Tear glands in our eyes drain into nasal cavity

Gas exchange is occurring between air and blood- passive diffusion 

• Air has high O2 levels ---> into blood
• Blood has high CO2 levels --->into air

Exit of air from the lungs

Respiratory center stops sending signals- muscles relaxes 

Involved in the exchange of gases and nutrients

O2 in

CO2 out

Absorption of Nutrients

Carry blood to the heart

Contains valves to ensure on-way blood flow

Blood Flow

&

Structure of Heart