cell notes

Cells

Unit 2

The Cell Theory

All organisms are composed of one or more cells.

7.1 Cell Discovery and Theory

Cellular Structure and Function

The cell is the basic unit of structure and organization of organisms.

Chapter 7

All cells come from preexisting cells.

Prokaryotic Cell

Simple structure


Contains a plasma membrane

Does not contain membrane-bound organelles

No Nucleus11,000x


Chapter 7

Eukaryotic Cell

More complex structure


Contains a plasma membrane

Contains membrane-bound organelles

Has a nucleus400x


Chapter 7


7.3 Structures and Organelles

Chapter 7

Plasma (Cell) MembraneThin, flexible boundary between the

cell and its environment

7.2 The Plasma Membrane


Allows nutrients into the cellAllows waste to leave the cell (Selectively Permeable)

Chapter 7

The plasma membrane is composed of the phospholipid bilayer.


A phospholipid means:a glycerol backbonetwo fatty acid chainsa phosphate group.


Chapter 7

Fluid Mosaic Model


The phospholipid bilayer allows other molecules to “float” in the membrane.

Other ComponentsProteinsCholesterolCarbohydrates


Chapter 7

Proteins


Transmit signals inside the cell Act as a support structure Provide pathways for larger substances to enter

and leave the cell


Chapter 7

Cholesterol


Prevents fatty acid tails from sticking together


Chapter 7

Carbohydrates


Identify chemical signals


Chapter 7

CiliaShort, numerous

projections that look like hairs


FlagellaLonger and less

numerous than cilia

Create movement with a whiplike motion

400x

26,367x

7.3 Structures and Organelles

Chapter 7

Passive Transport

Movement of particles from a high to low concentration across the membrane without using energy

7.4 Cellular Transport

Cellular Structure and FunctionChapter 7

High

Low

DiffusionMovement of particles from an area of high

concentration to an area of lower concentration



Chapter 7

Diffusion is controlled by


Temperature PressureConcentration

Dynamic EquilibriumWhen diffusion of material into the cell

equals diffusion of material out of the cell


Chapter 7

Facilitated Diffusion


Movement of materials across the membrane from a higher to a lower concentration by using proteins


Chapter 7

Osmosis


Diffusion of water across a selectively permeable membrane


Chapter 7

Blood CellPlant Cell

Isotonic Solution


Water and dissolved substances diffuse into and out of the cell at the same rate.

11,397x


Chapter 7

Blood Cell

Hypotonic Solution


Solute concentration is higher inside the cell.

Water diffuses into the cell.

Plant Cell

13,000x


Chapter 7

BLOWS UP the cell.

Plant Cell

Hypertonic Solution


Solute concentration is higher outside the cell.

Water diffuses out of the cell.

Blood Cell

13,000x


Chapter 7

SHRINKS the cell.

Active Transport


Movement of particles from low to a high concentration across the cell membrane using energy


Chapter 7

Low

High


Endocytosis

The cell surrounds and takes particles into the cell


Chapter 7

Chapter 7


Exocytosis

Secretion of material out of the plasma membrane


Protein pumpMoves three Na+ ions out of the cell and

two K+ ions into the cell Important for nervous system impulses

for transmitting information


Chapter 7

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_the_sodium_potassium_pump_works.html

Transformation of Energy

Energy is the ability to do work.

8.1 How Organisms Obtain Energy

Cellular Energy

Thermodynamics is the study of the flow and transformation of energy in the universe.

Chapter 8

Metabolism

All of the chemical reactions in a cell


Cellular Energy

Photosynthesis—light energy from the Sun is converted to chemical energy for use by the cell

Cellular respiration—organic molecules are broken down to release energy for use by the cell

Chapter 8

ATP: The Unit of Cellular Energy

ATP releases energy when the bond between the second and third phosphate groups is broken.


Cellular EnergyChapter 8

http://www.phschool.com/science/biology_place/biocoach/photosynth/overview.html

Light and pigments

• Photosynthesis requires light and the pigment chlorophyll

• The green pigment is the wavelength reflected rather than absorbed, by plants the most – so plants are green and other colors are absorbed

Overview of Photosynthesis

Photosynthesis occurs in 2 phases:

Cellular Energy

1. Light-dependent reactions (thylakoid)

2. Light-independent reactions/Calvin Cycle (stroma)

8.2 Photosynthesis

Chapter 8

Phase One: Light Reactions

The absorption of light is the first step in photosynthesis.

Cellular Energy

Chloroplasts capture light energy.

8.2 Photosynthesis

Chapter 8

Reactions of PhotosynthesisLight dependent reactions

• Grana are stacks of thylakoids in the chloroplast that contain the chlorophyll which captures sunlight

• Light dependent reactions take place in the thylakoids

Cellular Energy

8.2 Photosynthesis

Phase Two: The Calvin Cycle (Light-Independent)

In the second phase is the Calvin cycle, energy is stored in organic molecules such as glucose.

Chapter 8

Light independent reactionsThe Calvin Cycle

• The Calvin cycle or light independent reactions take place in the stroma of chloroplast

• Uses ATP and NADPH from light dep. Reactions to produce high energy sugars

http://www.biology.ualberta.ca/facilities/multimedia/uploads/alberta/Photo.html

http://www.pbs.org/wgbh/nova/nature/photosynthesis.html

http://www.biology.ualberta.ca/facilities/multimedia/uploads/alberta/Photo.html

http://www.pbs.org/wgbh/nova/nature/photosynthesis.html

Overview of Cellular Respiration

the chemical bonds of glucose are broken down in the presence of oxygen and produce energy.

8.3 Cellular Respiration

Cellular EnergyChapter 8

(Glucose) + (oxygen)---->(carbon dioxide) + (water) + energy* (ATP)

GlucoseGlycolysis

Cytoplasm

Pyruvic acid

Electrons carried in NADH

Krebs Cycle

Electrons carried in

NADH and FADH2 Electron

Transport Chain

Mitochondrion

Overview of Cellular Respiration

Mitochondrion


Cellular Energy

Cellular respiration occurs in 3 parts.

Glycolysis

Kreb’s Cycle

Chapter 8

Electron Transport Chain

Step 1: Glycolysis

Takes 2 ATP to start

Glucose is broken down in the cytoplasm by glycolysis (splitting glucose).

Occurs in the cytoplasm

Forms 2 pyruvate from 1 glucose


Cellular Energy

2 molecules of ATP and 2 molecules of NADH are formed for each molecule of glucose that is broken down.

Chapter 8

Step 2: Krebs Cycle


Cellular Energy

The series of reactions in which pyruvate is broken down into carbon dioxide

Occurs in the mitochondria

Chapter 8


Cellular Energy

The net yield from the Krebs cycle is:

6 CO2 molecules2 ATP8 NADH2 FADH2.

Chapter 8


Cellular Energy

Step 3: Electron Transport

Final step in the breakdown of glucose

Point at which most ATP is produced

Produces 24-32 ATP

Chapter 8

Summary FlowchartSection 9-2

Glucose(C6H1206)

+Oxygen

(02)

GlycolysisKrebsCycle

ElectronTransport

Chain

Carbon Dioxide

(CO2)+

Water(H2O)

Cellular Respiration

Glucose

Glycolysis Krebs cycle

Electrontransport

Fermentation (without oxygen)

Alcohol or lactic acid

Chemical PathwaysSection 9-1


Cellular Energy

Anaerobic Respiration

The anaerobic pathway after glycolysis

Two main types:

Lactic acid fermentation (muscles)

Alcohol fermentation (yeast & molds)

Fermentation

• A process in the absence of oxygen (anaerobic)

• Lactic acid fermentation – Occurs when body can’t supply enough oxygen to the muscles during exercise = soreness, burning, fatigue

Cell Tour

http://vcell.ndsu.nodak.edu/animations/flythrough/movie-flash.htm

cell notes

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