Friday, October 29, 2010
Develops in two stages:
1. The first exposure to the allergen causes sensitization (you get sensitive).
2. The following exposures of the same allergen cause allergy symptoms.
• Histamine – a chemical that reacts to an allergy
• We take anti-histamine when we get allergies to fight them off
1. Allergen enters the blood stream.
2. B cells make the antibodies
3. The antibodies attach themselves to the mast cell.
4. Allergen binds onto the antibodies on the mast cell.
5. Histamine is released and starts causing allergy symptoms.
Allergens usually tend to enter through the nose and the throat so symptoms are most abundant in these areas.
Anaphylactic shock – sudden releases of inflammatory chemicals into the body of people with extreme sensitivity to certain allergens such as:
• Bee stings
So what happens?
Blood vessels expand greatly causing a great drop in blood pressure, a condition also known as shock.
Anaphylactic shock can be fought off with injections of epinephrine (adrenaline).
Common Autoimmune Diseases
Rheumatoid Arthritis – causing damage and inflammation of bone joints due to T-cell attack
Juvenile Diabetes – a cell-mediated attack of insulin that produces cells in the pancreas
Multiple Sclerosis – T-cells attack the myelin sheath (fatty tissue) of neurons
Lupus – immune attack on skin and vital organs
Every disease or infection has a different reaction depending on how weak or strong your immune system is.
Immunological basis for organ/skin graft rejection?
Transplant Rejection – an immune system recognizes the donor’s cells or organs as foreign and starts attacking
Donors with self proteins that match the recipient’s as closely as possible are used in order to minimize rejection.
Drugs are used to hold back to suppress the immune system. The donors and recipients may not be related.
1. SCID (Severe Combined Immunodeficiency) – a case where someone does not have functional T and B cells; as a result, they do not have specific responses.
2. Hodgkin Disease – a type of cancer that affects the number of lymphocytes, affecting the T and B cells.
AIDS (Acquired Immune Deficiency Syndrome)
HIV attacks the helper T cells that activate T bells and B cells.
Since 1981, AIDS has killed more than 20 million people, and 40 million people are living with the virus. Over 1/3 of the adult population in Africa has been infected as well.
Death is usually not a result of HIV, but because of other life threatening infections.
Next Scribe: Yunsu Yu
Thursday, October 28, 2010
We started to plan out our independant spice labs. Accompanied with that was the assignment to get your experiment approved by Mrs. Andrews. When approved, we were to turn in a lab report up until the procedure part.
An independant lab that we invent and carry out by oursleves. We are to measure the zone of inhibition in the bacteria, Bacilis subtilis. We are to perform the lab and to write a lab report.
The finished lab report is due on 11/8/10. Guidelines are:
-Materials have to be LIQUID
-Must have TESTABLE AND MEASURABLE hypothesis
-Have multiple trials
-Can only use 4-5 Petri dishes
-Can vary in concentration, product brand..ect
-Compare and contrast products.
In your lab report, remember to:
- Include background on ALL of your materials (should vary with group members)
- Match your procedure with your group's
- Use roman numerals, letters, and numbers for every section of your report
- Have an ORIGINAL title
- Must incude how/when to gather data (give times; 24 hours, 2 days..ect.)
- Include charts and graphs
- Lab report guidlines on UP pg. 43 and in Survival pk. pg. 13
- HAVE IT IN CLASS!
- STUDY FOR TEST
- Read UP pgs 37-38
- Re-read chp 24
- Review notes
next scribe: Bridget S.
Wednesday, October 27, 2010
One was about the role of an antibody.
- complement proteins
- humoral immunity- provided by B-cells, defends primarily vs. bacteria and viruses present in body fluids
- clonal selection
- When an antigen enters the body fluids, it binds with B-Cells that have complementary receptors
- The B-cells are then activated; they grow and divide, creating effector cells
- These cells then secrete antibodies specific to that antigen
- plasma cells- make the antibodies
- memory cells- "remember," this is why you don't get the same exact infection again because your body produced the antibodies needed to fight that infection
- Cell-mediated immunity
- Respond to antigens that have already entered the body
- More "hands on" than B-Cells
- 3 kinds- Helper T-Cells, Cytotoxic T-Cells, and Supressor T-Cells
- Macrophages engulf a microbe, produce antigens, and displays the foreign antigens on the cell membrane
- it is essentially saying "I found something and I don't think it's good!"
- The Helper T-Cell binds to the macrophage at the site and determines if it is good or bad
- If bad, the Helper T-Cell divides, produces memory cells, and stimulates activity of cytotoxic T-Cells
- Identifies infected body cells and binds to them
- Discharges perforin which is a protein that creates a hole in the infected cell's membrane, causing it to die.
- This needs to happen because the infected cell has become a factory of pathogens and the body needs to have it shut down.
- UP pgs. 47 and 57
- UP pg. 5 What is Ecology Good For (E.C.)
- Work on Lab Report, Due: 11/8
- The Test may be on Tuesday, but please still plan on Friday!!!
- Claire T
Monday, October 25, 2010
Today, we reviewed bacteria and viruses at the beginning of class.
Friday's the test. Monday's the project.
Research Bacillus subtilis
THE IMMUNE SYSTEM:
There are three layers of defenses against pathogens. (Look at the chart on page 15 of your notes packet)
The defenses can either be specific or non-specific.
Non-specific defenses are the first line of defense and the second line. They are not specific because they do not know what is attacking them and will attack anything. rawr.
Specific defense is the third line of defense. It has specific jobs to kill specific diseases.
I. Nonspecific DefensesA.External Barriers-Set of physical barriers and chemical agents that prevent invaders from penetrating deep inside.Examples:
1. Hair and mucus
2. sweat, saliva, tears.
i. These are PUSHING the unidentified stuff out. They contain lysozyome
B. Internal Defenses-these are put into play when the invader gets past the external barriers.
II. Inflammatory Response
A. White blood cells.
1. They eat bacteria. They don't care what kind of bacteria, they just eat it. So, it's non specific.
i. Since they eat a lot of bacteria, they have a lot of lysosomes, to help breakdown the food
2. White blood cells do not clot the injury. That is the platelets job.
i. If the platelets clot too fast, meaning it doesn't allow the white blood cells to finish eating the bacteria, that causes infection.
B. Players of the Inflammatory Response.
1. Histamines. Causes vessels to dilate and leak fluid into wounded tissue, SWELLS.
i. Swelling is GOOD. Helps dilute toxins and bring extra oxygen
2. Prostaglandins. Inscreases blood flow to the wound area = RED and WARM.
i. Also sends pain signals to brain. AH! Brain, help me!3. Pyrons. travel to the hypothalamus (it's in the brain and it analyzes your blood.) They cause a low fever which is GOOD because the heat makes the enzymes work faster.
III. Lymphatic System
A. Two main functions
1. To return tissue fluid to circulatory syste
2. To fight infection.
It's a highway of vessels that touches upon every part of your body so they can react fast when tissue is damaged.
Scribe: Aliza R.
Thursday, October 21, 2010
"Nonspecific diseases". So, if you wish to look at the notes, go into moodle under Mrs. Andrews' name, and the notes should show up.
This hereby concludes today's blog
next scribe - CJ
o Chapter notes- (pg. 10-top 13)
We looked at some important notes
Bacteria Cell:o They have no nucleus
o Most have cell wall exterior to plasma membraneo 50% are Motile (can move)
o Sessile- stationary
3 types of bacteria:o Cocci: spheres
o Bacilli: rod-shaped
o Spirochete: spiral-shaped
Bacteria Reproduction:o Can reproduce if conditions are favorable
o Their cells divide through binary fission
conjugation - sexual reproduction with 2 different bacteria cells
Endospore:o Can survive extended periods in harsh conditions
o Lack of water/ nutrients
o Extreme temperatures
o Most are poisons
o Found in some prokaryotes
o Outer cell produces the Endospore
o Outer cell may disappear, but Endospore survives
o Some can remain like this for centuries
Impact of Prokaryotes on Humans:o Disease- causing Bacteria
o Exotoxins: poisonous proteins secreted by the bacteria cells
o Often causes vomiting and diarrhea
o Endotoxins: chemical components of the cell wall on the cell
o Often causes fever, aches, drop in BP
Power of Antibiotics:o Zone of Inhibition: the areas where the growth of bacteria is prevented (inhibited) by an antibiotic or other substance
next scribe - Skyler
Wednesday, October 20, 2010
Viruses are considered both life and non life, since they ahve characteristics of both.
Life: Highly organized with genes
Non-Life: not cellular, cannot reproduce on own
Viruses infect a living cell. one way they do this is the lyctic cycle, where DNA is injected by virus into host cell to produce copies of virus.
DNA viruses usually reproduce in host cell's cytoplasm, sometimes in nucleus.
Prokaryotes have been around for 2 billion years.
Next Scribe - Nick
Sunday, October 10, 2010
Unit 2 - CELLS
MITOSIS = cell division
Scribe Post for Friday, 10/8/10
Cells divide to replace damaged cells, reproduce organisms, to grow, to transfer genes from cell to cell, and for a unicellular organism to become multicellular
TYPES OF REPRODUCTION
Sexual (MEIOSIS)- fertilization of an egg by sperm (each contain half of the parent cell's chromosomes), occurs in reproductive organs (ovaries/testes)
Asexual (MITOSIS)- no fertilization at all, parent and offspring have the same genes, binary fission (organism splits into 2, found in single celled organisms)
-Contain almost all genes of a eukaryotic cell
-Visible with light microscope during cell division
-Chromatin (invisible) are masses of long thin fibers, contain DNA/protein
-Before cell division, chromatin coils up to form chromosomes
-Humans have 46 chromosomes (varies by species)
-Each chromosome can have over 1,000 genes
-Genetic material must be doubled before cell division to make sure that the daughter cells match the parent cell
--Sister chromatids are identical copies of each other connected at the centromere
--Daughter cells are the result of cell division, DOES NOT IMPLY GENDER
The Cell Cycle
Interphase (Pre-Mitosis) - 90% of cell cycle
-GI (Gap 1) - cell grows 2x bigger, protein synthesis, more organelles, 2x cytoplasm
-S (Synthesis) - chromosome replication (in nucleus)
-G2 (Gap 2) - Final preparation before division
Prophase - CHROMOSOMES AND SPINDLE FIBERS COME, NUCLEAR ENVELOPE GOES!
-Chromosomes coil/condense to become visible
-Sister chromatids connected at centromere
-Nuclear envelope breaks down
-Spindle attaches to centromeres and move chromosomes to center of cell
Metaphase - DUPLICATED CHROMOSOMES CENTER UP!
-Spindle completely formed
-Centromeres on chromosomes are lined up on equator between the poles
-Spindle is attached to each sister chromatid, pushes chromosomes to center
Anaphase - DUPLICATED CHROMOSOMES SEPARATE AND MIGRATE!
-Sister chromatids are separated and each are now known as daughter chromosomes
-Motor proteins on centromeres move chromosomes toward opposite pole of cell
-Spindle attached to chromosomes shorten
-Spindle not attached to chromosomes lengthen to extend cell and force poles further apart to prepare for daughter cells
Telophase - NUCLEAR MEMBRANE FORMS AROUND NEW CHROMOSOMES!
-Begins once chromosomes reach poles
-Opposite of Prophase
--Nuclear envelope REAPPEARS
--MITOSIS IS NOW FINISHED
Cytokinesis - CYTOPLASM DIVIDES TO FORM 2 DAUGHTER CELLS!
-Begins during telophase
-'CLEAVAGE' in animal cells
-cleavage = indent at equator of cell that pinches cell in 2
-Formed by ring of microfilaments inside cell membrane
-In plant cells, cell plate forms by starting in center of cell and moving outward to bisect cell
Cell Cycle Control
-Cells that are not directed by the cell cycle divide out of control
-Result is a benign tumor (abnormal mass of normal cells)
--can cause problems depending on location
--as it grows, displaces normal tissue
-Cancer cells have faulty cell cycle, divide out of control
-Malignant tumor = lump that results from division of cancer cell
-Metastasis = spreading of cancer cells to other organs
-Cancer is named for where they begin
--Carcinomas - originate in external/internal coverings of body
--Sarcomas - originate in tissues that support body
--Leukemia - cancer of blood forming tissue (bone marrow)
--Lymphomas - cancer of blood forming tissue (lymph nodes)
-Cancer cells exposed to high-energy radiation disrupt cell division
-Radiation destroys cancer cells without harming normal cells
-Bad side effects (sterility)
-Drugs that disrupt cell division
-Antimitotic drugs - prevent cell division by interfering with spindle formation
NEXT SCRIBE: Davin L
Thursday, October 7, 2010
First Mrs. Andrews collected the UP pages 41 and 42.
IMPORTANT DATE CHANGE- Unit 2 test will be Thursday Oct.
Naked Egg Demo #3:
We looked at the egg. This time it was in corn syrup. Here is how it looked like...
• There was almost no shell left.
• The top was caved in a little.
• The inside of the egg was hypotonic and the corn syrup outside was hypertonic because the syrup has a much higher concentration of solute.
• The color of the egg was not pure white anymore, it had a little yellow color.
Went to the Computer Room
• Started UP pages 49-51.
• The websites were about Mitosis.
- Finish UP pages 49-51
- Read lab on UP pages 53-60
- Study for Unit 2 Test on Thursday
Wednesday, October 6, 2010
Egg soaked in vinegar:
Hard shell gradually broken down by vinegar
- surrounded by bubbles (slowly eat away shell)
- soft, gooey feeling
Normal and Plasmolyzed Cells Demo
Purpose: To see the differerence(s) between a normal and plasmolyzed cell
Hypotonic: normal elodea leaf cell (good)
- tap water added
- cell membrane doesn't change
Hypertonic: plasmolyzed elodea leaf cell (bad)
- salt water added
- vacuole shrunk
- empty space between membrane and cell wall
- Endocytosis: 3 types
- Finish Lab
- Read Chapter 8 p.121-129 (Mitosis and Cancer)
Tuesday, October 5, 2010
First we talked about the naked egg experiment, in which an egg is placed in various substances to prove the diffusion that takes place while the egg is in the substances.
Next we set up for the lab.
Then we took a quiz and when we were finished recorded our results from the lab.
The lab was about diffusion, and was a cellophane dialysis tube with starch, water, and glucose, sitting in a beaker of iodine and water. When the tube was observed after the quiz the water had turned almost black inside the tube and the beaker seemed to have stayed the same. The color change was because of the combination of iodine and starch within the tube. The iodine got in the tube because of diffusion and because it started with a higher concentration in the beaker and moved to lower concentration in the tube.
You know the iodine diffused in the lab because of the color change in the tube, showing the presence of iodine and starch.
The starch however did not diffuse to the outside of the tube, because if it had, the water in the beaker outside the tube would have been black like the inside of the tube, because the iodine and starch would have mixed. It didn't diffuse because it was a lower concentration than the occupants of beaker around the tube.
The glucose didn't obviously diffuse during the lab, or the water would have been a bit darker in the beaker because glucose and iodine turn dark brown when mixed.
Iodine and water diffused through the membrane of the cellophane tube.
Starch and glucose did not, that we could observe, diffuse through the cellophane tube membrane.
The failure of starch to diffuse through the membrane could have been because the molecules were bigger and less concentrated and didn't need to diffuse to an area of lower concentration to be spread out.
Materials can't pass through selectively permeable membranes going different directions at the same time, because it's selectively permeable and only certain amounts of certain substances can pass through at once.
The materials that diffused in opposite directions during this experiment were water and iodine.
A cell is dead when it is in complete equilibrium with its surroundings because nothing is being transferred. No energy or materials are being passed back and forth therefore the cell isn't functioning and would be dead.
It's harmful to add salt water to a fresh water plant because the salt soaks up the water that the plant needs to absorb, and the plant becomes dehydrated.
Next scribe Christine K.
Monday, October 4, 2010
- The cytoskeleton is a network of fibers extending throughout the cytoplasm and it helps to hold the cells shape together.
- They are the "muscles" for movement.
- The three types are microfilaments, intermediate filaments, and microtubules.
- Helical rods made out of a globular protein called actin.
- These help the cell move and change their shape.
- Actin and other fibers work together to make muscles contract.
- These are ropelike fiberous proteins.
- They have reinforced rods to bear tension and they anchor organelles.
- Straight, hollow tubes that are made of globular proteins. They are called tubulins.
- Globular molecules are like small marbles.
- They make themselves longer by adding tubulin subunits to one end.
- Their functions are providing shape, tracks for organelles to move within teh cytoplasm, they guide the movement of chromosomes during cell division, and move the cilia and flagella.
- Shorter than flagella and they are more numerous.
- Propel protists; single celled organisms.
- Can be damaged by smoking and line the respiratory tract.
- The cilia push debri up and out of the body.
- A type of transport.
- Propel sperm, other animals, and protists.
- Microtubules form a 9 + 2 arrangement which means that there are 9 doubles of microtubules forming a ring around one double.
- These make up one cilia or one flagella
- To move the cilia or flagella, a motor protein called dyneins is needed. It grabs ontioo an adjacent microtubule doublet.
- These structures are flexible.
- Basal bodies and centrioles have identical structures.
- Basal bodies are anchor cilia or flagella in the cytoplasm.
Membranes of the Cell
- Plasma Membrane - cell's outer membrane (Cell Membrane)
- Endomembranes - smooth and rough endoplasmic reticulum, golgi, vacuole, and lysosome (only these internal oragnelles can break apart)
- Membranous envelopes - nucleus, chloroplast, and mitochodria (have 2 membranes)
- Semi-permeable - allow some substances to pass through, but blocks the passage of other substances. (only small things can go through)
- Membranes enclose and maintain the specific chemical environment.
- Every membrane carries out its specific functions.
- Two layer membrane called phospholipid bilayer.
- Made of proteins and lipids
- Contains two fatty acids instead of three (hydrophobic)
- Contains a phosphate group in the place of the third fatty acid (hydrophilic)
Membranes and Proteins
- Specific proteins are inserted into the phosolipid bilayer to:
- Attach to the cytoskeleton
- Talk to other cells
- Enzyme Activity
- Transporting passively and actively
- Two cells holding each other, intercellular joining
- Cell-cell recognition
- Membranes are not rigid.
- Protiens move freely on the membrane and do not just stay in one spot.
- This is called the fluid mosaic model.
Diffusion and Osmosis
- In diffusion, the molecules move.
- In osmosis, the water moves.
- Diffusion: the tendency of molecules to move from a high concentration to a low concentration until equilibrium is reached.
- Equilibrium is when the conecentration of either side it equal.
- Diffusion across a membrane.
- Cell does not use any energy for diffusion.
- Selectively permeable membrane.
- Water, O2, and CO2 go through the membrane because they are small.
- Osmosis: passive transport of water across a semi-permeable membrane.
- Solute = what is dissolved.
- Solvent = what the solute is dissolved in.
- Water moves across the membrane, not the solute.
- High concentration of solute and lower for solvent.
- Hyper = above.
- Plasmolysis = losing water.
- Cells will shrivel up if there is not enough water.
- High concentration of solvent and lower for solute.
- Hypo = below.
- Lysing = bursting of a cell.
- Good for plant cells.
- Everything is equal.
- Isos = equal.
- Animal cells like this, but plant cells do not.
Effect on living animal cells
- Osmoregulation - control of water balance.
- Animals must use this to survive.
- Blood cells love this.
Effect on living plant cells
- Most plants thrive in a hypotonic environment when the vacuole is full.
- Plants become wilted in a isotonic environment.
Posted on 10/4/2010
Next Scribe: Katie B.
Friday, October 1, 2010
Today in class, we took notes on cells and their functions in the green packet.
What are the structures? What do they do?
All cells come in different shapes and sizes, and it is impossible to see a plant or animal cell with the naked eye.
1. Light Microscope – visible light passes through the specimen, glass lenses enlarge the image. (the microscopes we use in class)
· Resolving power = 0.2 micrometers (one thousand micrometers in a millimeter)
2. Electron Microscope – uses beam of electrons instead of light
· Resolving power = 0.2 nanometers ( hundred thousand in a millimeter)
A. Scanning electron microscopes look at the actual surface of a cell
B. Transmission electron microscopes explore the inside of a cell
I. Prokaryotic vs. Eukaryotic
Prokaryotic cells contain bacteria and archaea. Eukaryotic cells contain protists, plants, animals, and fungi.
Pro = before Eu = true
Karyon = kernel (nucleus) Karyon = kernel (nucleus)
II. Plant Cells and Animal Cells
Plant Cells Contain:
· Plasma membrane
-Chloroplasts/plastids (not green)
· Cell walls (forms a rigid, rectangular shape, not flexible)
· Square morphology
Animal Cells Contain:
· Plasma membrane
· Centriole (cell division)
· Round morphology (a more circular shape, flexible)
III. Cell Organelles
Organelle – (little organs) structure with a specialized function within a cell.
Organelles are eukaryotic.
Organelles are made up of a cell membrane that contains a nucleus, within a cytoplasm.
The nuclear envelope contains a double membrane with pores that surround the nucleus. Little things are allowed to get in while big things stay inside. DNA is attached to a protein found in the nucleus in the form of chromatin (uncondensed, not currently dividing).
46 chromosomes in humans
Nucleolus is found in the nucleus. Ribosome production occurs in the nucleolus.
Nucleolus --> Ribosomes --> Protein
There may be one or more nucleolus per nucleus.
Ribosomes look like small dots in the cytoplasm and in the Rough Endoplasmic Reticulum (RER). Ribosomes assist in protein synthesis by making enzymes and proteins for an organism. Ribosomes are responsible for providing proteins/enzymes.
VI. Rough Endoplasmic Reticulum
RER’s look rough and grain-like due to ribosomes. They produce membranes and secretary proteins.
VII. Smooth Endoplasmic Reticulum
Makes lipids (steroids and hormones)
Cells in the liver detoxify (take toxins out) drugs and other poisons inside the blood.
VIII. Golgi Apparatus
Also known as the “UPS truck”
Finishes, stores, and distributes chemical products of the cell.
Final products are disturbed to other organelles or out of the cell membrane.
Means breaking down the body
Breaks down proteins, fats, polysaccharides, and nucleic acids.
Fuses with food vacuoles for digestion.
Useful products of digestion leave the lysosome and nourish the cell.
Destroys harmful bacteria.
Recycles damaged organelles.
Lysosomal Storage Diseases –
Lysosomes become enlarged and interferes with other cellular functions.
Ex: Tay-Sachs disease – ravages the nervous system
· Lacks lipid digesting enzyme and nerve cells in the brain which accumulates excess lipid and results in functioning improperly.
Sizes and functions:
Central vacuole in a plant
· Store organic nutrients
· Absorb water – cells expand
· Pigments in petals to attract insects
· Contain poisons to deter plant eating animals
Organelles of plants and protists that perform photosynthesis.
Stroma – thick fluid inside inner membrane
Grana – located in stroma, network of membrane enclosed tubes and disks, solar power packs (traps the sun’s energy and convert is)
Site of cellular respiration
Takes chemical energy from sugars and converts it to ATP (for of energy our cells use).
Found in most eukaryotic cells
Outer membrane and inner membrane that has multiple folding called cristae.
A network of fibers extending throughout the cytoplasm
Skeleton for support and cell shape.
The muscles are used for movement, rearrangement of cytoskeleton can cause cell or parts of the cell to move.
3 types of fibers:
Next scribe - Sonali