Tuesday, April 26, 2011


Yunsu Yu

4 Ways that We Regulate Our Internal Environment:

1. Homeostasis: (Review from yesterday...)
  • Steady state. While there are large external fluctuations, our homeostatic mechanisms take those in and make them smaller fluctuations.
  • Although we use homeostasis, there are still changes but in ranges that are tolerable=dynamic state.
2. Negative/Positive Feedback:
  • Negative Feedback: When something is too much and it turns off.---think of a thermostat, you set it to 72 degrees and when it gets too hot inside, the thermostat turns on and when the temperature goes over 72, it turns off because it is too hot at the moment.----"on and off" switch.
  • Positive Feedback: Process that intensifies-makes even more---"on and on more" switch.
  • Usually negative feedback is used especially in our bodies, but positive feedback is still present.
3.Thermoregulation: maintenance of internal body temperature.
  • we are endotherms, we make our own heat from metabolism: sum of chemical reaction=heat.
  • ectotherms use the sun for heat. Ex:Reptiles.
  • Heat loss is regulated by hair, fur, migration, huddling, clothing, sweating, and panting.
  • When we get cold our blood vessels constrict near the surface this is what causes shivering and goosebumps. ---this leads to a decrease in exchange from environment.
  • Our brains are the control center. This is the thermostat of our bodies and uses Negative feedback when needed.
4.Osmoregulation: control of the gain or loss of water and dissolved solutes.
  • Gain water from drinking or eating
  • Through urinating, breathing, and perspiring we lose water. ---the kidneys help regulate this!
When someone has a fever should you lower it?
  • It depends: sometimes a fever is good because it kills bacteria growth and speeds up the repair of damaged tissue. (100-102 degrees)
  • But can also be harmful because it damages body proteins and you can die. (104 degrees and over.)
  • Fever-caused by "pyrogens" these raise the body temperature.
The Excretory System: Kidney, Skin, Lungs..etc
  1. Kidneys are the main organs. They filter blood and take out the "bad" stuff.

  • We have 2 kidneys that are smaller than your fist and are located in the lower back.

  • They contain tubules, capillaries. Throught the tubules blood enters and it filtrates water, glucose, salts, and amino acids.
  • Waste products need to be excreted: urea, extra water, extra salt . (sweat)
  • The four Processes of the Kidney:

  1. Filtration: Small things only enter the tubule.
  2. Reabsorption: Water and solutes are returned. Take back what we want.
  3. Secretion: Specific substances are removed from blood-2nd chance to get everything-drugs go through here (medicine.)
  4. Excretion: Urine exits body. Leftover waste.
We then took a look at the kidney and labeled the parts:

HW: Design a QUiZ due May 12th

Do UP. 53-57 due Thursday

Do Up. 7-11 due Thursday


next scribe: Kristen M.

Monday, April 25, 2011

Unit 11: Body Tissues, Excretion, and Digestion

Anatomy = the study of the structure of an organism and its parts.
Physiology = the study of the function of these structures.

5 Levels of Organization:
  • Cellular Level
  • Tissue Level
  • Organ Level
  • Organ System Level
  • The Organism Itself
Four Main Types of Tissues
1. Epithelial
3. Muscle
4. Nervous
Epithelial Tissue:
covers surface of body, lines organs and cavities
*replaced completely every two weeks*
Connective Tissue:
sparse; scattered through an extracellular matrix; six major types
  1. Loose Connective Tissue (webbed)
  2. Adipose Tissue (fat)
  3. Blood
  4. Fibrous Connective Tissue
  5. Cartilage
  6. Bone
Loose: holds organs in place; loose weave, but strong; has elastic fibers -
"Snap it while you can!" - Christine Kim
Adipose: stores fat; fat bubbles expand when fat is consumed
Blood: red and white blood cells in plasma(liquid)
Fibrous: forms tendons(muscle to bone) and ligaments(bone to bone)
Cartilage: rubbery, but strong; heals slowly
"Sharks are made entirely of cartilage." - James Cho
Bone: rigid with calcium deposits; hard, but not brittle
Muscle Tissue:
MEAT! contract when stimulated by a signal
-3 types:
Skeletal: voluntary, striated(alignment), fixed number(weight lifting only expands)
Cardiac: only in the heart; striated, involuntary(do not have to think to make heart beat)
Smooth: walls of organs, blood vessels; involuntary, not striated
Nervous Tissue:
sends information from one body part to another

"Open" System
we exchange chemicals and energy with surroundings continuously

In = nutrients and oxygen
Out = waste and carbon dioxide
We exchange indirectly via our circulatory system

It means keeping a steady state - internal body maintains constant conditions even when external environment changes.

Next Scribe: Nick.

Wednesday, April 20, 2011

April 19. 2011

  • 6 carbons in, 6 carbons out (glucose, 2 pyruvic acid)
  • 2 ATP needed at beginning as investment
  • 4 ATP released, 2 ATP gained at end
  • REMEMBER: break bond--> release energy. form bond--> store potential energy
  • 2 Reactants: NAD+ and Coenzyme A
  • 3 Products: CO2, NADH (potential energy/energy carrier), Acetyl-CoA
  • 6 carbons in, 6 carbons out
  • Reactants: Acetic acid, ADP+P, 3 NAD+, FAD
  • Products: 2CO2, 2ATP, 3 NADH, FADH2 (energy carrier)
  • concentration gradient similar to photosynthesis,
  • H+ ions move from high concentration to low concentration by diffusion,
  • fuels ATP sythase to create ATP from ADP (34 total)
  • O2 is final electron acceptor, bonds with H+ to form H2O
  • example of anaerobic function: sprinting
  • anaerobic: doesn't require oxygen
  • aerobic: requires oxygen
  • facultative anaerobe can break down with or without oxygen
  • obligate anaerobe is poisoned by oxygen
  • obligate aerobe dependent on oxygen to survive
  • body cells facultative anaerobes
  • human body is an obligate aerobe
  • Only 2 ATP produced compared to 34-38 in cellular respiration
  • anaerobic glycolysis is included in process
  • lactic acid is waste product
  • anaerobic
  • Yeast produces ethyl alcohol and CO2
  • anaerobic
Next Scribe: Sonali

Saturday, April 9, 2011


Photosynthesis Chemical Reaction (Please Memorize!!!!)
  • 6 CO2 + 6 H20 = C6H1206 + 6 O2
  • (The numbers are actually subscripts and the "equals" sign is actually an arrow, meaning "yield")
  • Reactants= 6 CO2 (Carbon Dioxide), 6 H20 (Water)
  • Products= C6H1206 (Glucose), 6 02 (Oxygen Gas)
  • Electrons added to Carbon dioxide to produce sugar Water molecules split and release oxygen gas (Sunlight provides the energy for this)
  • Simple Summary of Photosynthesis

Light Reactions and Calvin Cycle- 2 different cycles but work together

  • Light Reactions
  • convert solar energy to chemical energy
  • make ATP (for energy storage) and NADPH (is an electron carrier)
  • Reactants: NADP+ and ADP and Water (H20) and Light
  • Products: Oxygen and ATP and NADPH
  • Happens in thylakoid
  • Calvin Cycle
  • "light independent cycle" or "dark reactions"
  • makes sugar from CO2
  • uses ATP and NADPH from light reactions
  • Reactants: CO2, ATP, NADPH
  • Products: Sugar (there are other products too; any other organic product can result also)

Products of Light Reactions are needed for Calvin Cycle and products of Calvin Cycle needed for Light Reactions (Dependent on each other)

Light Reactions

(More Detailed)

  • Light is energy!!!
  • Sunlight- radiation or electromagnetic energy
  • Visible Light is from 380-750 nm (wavelength)
  • What we can see- ONLY light reflected from an object

EX- green leaves absorb red-orange and blue-violet light; reflecting green light (chloroplasts convert that absorbed energy into chemical energy)

  • Chloroplast Pigments (found in photosystems)
  • Chlorophyll a-
  • absorbs blue-violet light and red light
  • participates directly w/ light reactions
  • Chloropyll b-
  • absorbs blue and orange light
  • increases range of light that can be absorbed (helps light reactions)
  • Carotenoids-
  • absorbs blue-green light
  • absorbs and dissipates excessive light that could damage chlorophyll a

Photosystems and Light

  • Photon- fixed quantity of light energy
  • pigment molecules absorb photons of light, "exciting" the electrons so that they have more energy (higher energy state)
  • electrons "falls" back to normal state (because the more energy they have the more unstable they are)
  • releases energy (in form of light or heat)

arrows=light and heat energy being released as electron falls back to normal state

    • Photosystems- have clusters of pigment molecules that act as antennae for photons of light
    • Photons of light "jump" from pigment to pigment until they reach the Reaction Center (has chlorophyll a)
    • Next to Reaction Center= Primary Electron Acceptor
    • traps the excited light energy into ATP or NADPH

    2 types of Photosystems

    • Water-splitting
    • light energy to extract electrons from water
    • releases oxygen as waste product
    • NADPH Producing
    • produces NADPH by transferring light excited electrons from chlorophyll to NADP+
    • Electron transport chain
    • connects the 2 photosystems, releases energy used to make ATP

    • ATP Synthase- uses energy stored by H+ gradient to make ATP
    • H+ molecules= more on the inside than on the outside, so they want to move to the outside


    Read CH. 7

    Pre-lab UP pg. 9-12

    Next scribe= Kristen :):)

    Thursday, April 7, 2011


    End of Chemistry notes:

    Chemical reaction: the chemical composition of matter is changed in a reaction

    - in order to have a balanced chamical reaction, the number of each element must be the equal on both sides




    -Photosynthesis feeds the biosphere

    -converts energy from sun energy into chemical energy of organic compounds

    -occurs in plants, some protists and some bacteria

    -Autotrophs- make own food, need inorganic compounds to make organic compounds, these are the producers

    -Heterotrophs- cannot make its own food, they eat, dependent on autotrophs, these are the consumers

    Photosynthesis occurs in CHLOROPLASTS (mainly the leaves of a plant)

    -double membrane envelope

    -inner membrane encloses stroma- fluid where sugars are made

    -thylakaids- sacs in stroma

    -grana=stacks of thylakaids


    Homework: read chapter 7

    Next Scribe: bridget :)

    Wednesday, April 6, 2011


    Today, the Fast Plant was due, so everyone make sure that you get that in. Also, today we continued some Basic Chemistry Notes (We couldn't do much because of the late arrival). One important note is that molecules, a new term, are groups of atoms that are joined together through chemical bonds. The big thing was the main difference between ionic bonds and covalent bonds, which are both tyes of chemical bonds. Remember that: Ionic bonds involve the transfer of electrons. And covalent bonds involve the sharing of electrons between atoms. Examples: ionic bond = table salt molecules, and covalent bonds = water molecules As a general note: remember that atoms are the basic unit of matter. Elements are substances that are made of only one type of atom. Compounds are substances that are made up of two or more elements. And molecules are particles that are made up of two or more different types of atom. Next scribe = Claire