Cells and Their Cells and Their EnvironmentEnvironment

Chp 4Chp 4

I. Cell MembraneI. Cell Membrane

a.a. Cell membrane also known as Cell membrane also known as plasmaplasma membrane, membrane, selectively permeableselectively permeable membrane, and membrane, and semi-permeablesemi-permeable membrane.membrane.

b.b. The cell membrane maintains The cell membrane maintains homeostasishomeostasis by by controllingcontrolling substances substances entering and leaving cell.entering and leaving cell.

c.c. The cell membrane is a The cell membrane is a fluidfluid phospholipid phospholipid bilayerbilayer (double layer) with (double layer) with proteins.proteins.

d.d. The phospholipid heads The phospholipid heads attract attract to to water (water (hydrophillichydrophillic).).

e.e. The phospholipid tails The phospholipid tails repelrepel water water ((hydrophobichydrophobic).).

f.f. Proteins Proteins are the workers of the cell are the workers of the cell membrane.membrane.

g.g. Carrier/TransportCarrier/Transport proteins help proteins help move substances across cell move substances across cell membrane.membrane.

A.A. PassivePassive transport is the movement transport is the movement of a of a substancesubstance across a cell across a cell membrane membrane withoutwithout the use of the use of energy (ATP) energy (ATP) from the cell.from the cell.

B.B. During passive transport During passive transport substances move substances move downdown the the concentration concentration gradient gradient from an from an area of area of highhigh concentration to an concentration to an area area lowlow concentration concentration

II. Passive TransportII. Passive Transport

1.1. Concentration Gradient- Concentration Gradient- DifferenceDifference in the concentration of in the concentration of substancesubstance across a spaceacross a space

2. Equilibrium- concentration of a 2. Equilibrium- concentration of a substancesubstance is is equalequal throughout a throughout a spacespace

D.D. Types of Passive TransportTypes of Passive Transport1)1) Simple Diffusion-Simple Diffusion- the movement of a the movement of a

substance substance (very (very smallsmall or or neutralneutral molecules) from an area of molecules) from an area of highhigh concentration to an area of concentration to an area of lowlow concentration concentration across the across the lipid bilayerlipid bilayer..

Ex. Blue dye demo, smells Ex. Blue dye demo, smells

(Discuss solvent, solute and solution)(Discuss solvent, solute and solution)

2.2. OsmosisOsmosis: the diffusion of : the diffusion of waterwater only.only.

Prefixes refer to the concentration of Prefixes refer to the concentration of the the solutesolute (substance being (substance being dissolveddissolved))

Hypotonic- less solutesHypotonic- less solutes

Hypertonic- more solutesHypertonic- more solutes

Isotonic- equal solutesIsotonic- equal solutes

Hypotonic solution (water moves into the cell)

Hypertonic solution (water moves out of the cell)

Isotonic Solution (water moves in and out at the same rate)

CONTRACTILE VACUOLES-pump out excess water (only found in unicellular organisms that live in water)

TURGOR PRESSURE= the amount of water pressure in the plant cell

Which hose has more Which hose has more turgor pressure?turgor pressure?

3) Diffusion through 3) Diffusion through ion channels-ion channels- ion ion channels are channels are proteinsproteins that have a pore that have a pore through which charged through which charged ionsions can cross the can cross the cell membrane (ex. Nacell membrane (ex. Na+1+1, K, K+1+1, Cl, Cl-1-1, Ca, Ca+2+2))

4) 4) FacilitatedFacilitated Diffusion- uses a Diffusion- uses a carriercarrier protein protein to move substances through to move substances through cell membranecell membrane

(ex. Large molecules such as (ex. Large molecules such as glucoseglucose & amino & amino acids)**fasteracids)**faster

Animations of Passive Animations of Passive TransportTransport

http://www.northland.cc.mn.us/biology/Biology1111/animations/passive1.htmlhttp://biomedicum.ut.ee/armpgb/1kursus/Ani_5.swf

III. Active TransportIII. Active Transport

A.A. Movement of substances from Movement of substances from areas of LOW concentration to areas of LOW concentration to HIGH concentrationHIGH concentration

B.B. REQUIRES ENERGYREQUIRES ENERGY FROM THE FROM THE CELL!CELL!

C.C. Types:Types:

1. Sodium-Potassium Pump- a protein 1. Sodium-Potassium Pump- a protein pumps 3 Napumps 3 Na+1+1 out and 2 K out and 2 K+1+1 in the cell in the cell

**important b/c too much Na**important b/c too much Na+1+1 is toxic and is toxic and cells need Kcells need K+1+1

http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/animations/ion_pump/ionpump.html

2. Vesicles- moves very large molecules either in or out of the cell (ex. proteins & polysaccharides)

a) the cell membrane forms a pouch around the substance and pinches off from the membrane & forms a vesicle

2 processes

i. Endocytosis- moves substances in the cell by either phagocytosis (cell eating) or pinocytosis (cell drinking)

ii. Exocytosis- move substances out of the cell

http://highered.mcgraw-hill.com/olc/dl/120068/bio02.swf

http://www.stolaf.edu/people/giannini/flashanimat/cellstructures/phagocitosis.swf

Animations of Active Animations of Active TransportTransport

http://www.northland.cc.mn.us/biology/Biology1111/animations/passive1.html

Ch. 5- EnergyCh. 5- Energy

I. Photosynthesis- I. Photosynthesis- the process of the process of using using light energylight energy to produce to produce glucose glucose & oxygen& oxygen

*Drawing of Photosynthesis

H2O

LIGHT

ENERGYChlorophyll- capture light O2 given

off

(we breathe it!)

H2O splits

LIGHT DEPENDENT REACTION

LIGHT INDEPENDENT REACTION

CO2 in

Given off evaporated

6(CO2 + H2) C6H12O6 H2O

MITOCHONDRIA AND O2 release energy by cellular respiration

air

roots

air glucose

evaporation

Light Dependent Reaction: Light Dependent Reaction:

HH22O + light energy O + light energy OO22 + H + H22

Dark (Light Independent)Reaction: Dark (Light Independent)Reaction:

HH22 + CO + CO22 C C66HH1212OO66 H H22OO

END RESULT: Produces OEND RESULT: Produces O22 and Glucose and Glucose (C(C66HH1212OO66) which drive cellular respiration) which drive cellular respiration

II. Cellular Respiration- breaks down II. Cellular Respiration- breaks down glucose to make energy (ATP) for the glucose to make energy (ATP) for the cell, occurs in the mitochondriacell, occurs in the mitochondria

A. 2 typesA. 2 types1. 1. Aerobic Respiration-Aerobic Respiration- occurs in occurs in

the presence of oxygen, produces 38 the presence of oxygen, produces 38 ATP each cycleATP each cycle

2. 2. Anaerobic RespirationAnaerobic Respiration- occurs - occurs when oxygen is not available, when oxygen is not available, produces only 2 ATP each cycleproduces only 2 ATP each cycle

END RESULT- Produces Energy, COEND RESULT- Produces Energy, CO22 & H& H22O which drive photosynthesisO which drive photosynthesis

Comparison of EquationsComparison of Equations

PhotosynthesisPhotosynthesis

HH22O + COO + CO22 + light (energy) -> + light (energy) -> CC66HH1212OO66 + O + O22

Cellular RespirationCellular Respiration

CC66HH1212OO66 + O + O2 2 -> H-> H22O + COO + CO22 + ATP + ATP (energy)(energy)

Photosynthesis andPhotosynthesis and Cellular Respiration Cellular Respiration

o makesmakeso usesuseso makesmakeso Occurs in lightOccurs in light

o Occurs in Occurs in ChloroplastChloroplast

o Plants onlyPlants onlyo usesuses

Cellular RespirationCellular Respiration

o usesuseso makesmakeso usesuseso Occurs day & nightOccurs day & nighto Occurs in Occurs in

MitochondriaMitochondriao Plants & AnimalsPlants & Animalso makesmakes

Photosynthesis

Glucose?

CO2?

O2?

Day /night?

Organelle?

Plant/Animal?

H2O?