CH 3 Cells are the smallest units of life. The Cell Theory 1.All living things are composed of one or more cells. 2.Cells are the basic units of structure.

CH 3CH 3

Cells are the smallest units of life

The Cell Theory

1. All living things are composed of one or more cells.

2. Cells are the basic units of structure and function.

3. Cells are produced only from existing cells.

All living things have cells

Unicellular creatures have

1 cell

Multicellular creatures have 2 or more cells

ProProkaryotickaryotic(Pre) (Pre) ( Nucleus)( Nucleus)

• Always single- celledAlways single- celled

• lacks organelleslacks organelles

• Few specialized functionsFew specialized functions

• BacteriaBacteria are the are the onlyonly groupgroup of of organisms that are prokaryotic!!!organisms that are prokaryotic!!!

EuEukaryotickaryotic(True) (True) ( Nucleus)( Nucleus)

• Single-celled or multi-celled

• Has many organelles

• Specialized functions

EX: nerve cells: for transmitting info

• All other living things EX: (Plants, Animals, Fungi)

Nerve Cell

CELLS:

What do you think What do you think these cells are?these cells are?

Cell OrganellesCell Organelleslittle “organs” that have

specific jobs in a cell                

The DifferencesANIMAL CELL

• Roundish– Lysosomes– Centrioles

PLANT CELL

• Squarish– Chloroplast– Cell Wall– Central Vacuole

A cell is like a cell phone factory

CELL MEMBRANEFunction: controls what goes in & out & makes

cells waterproof

Facts:• Selectively Permeable: only lets certain

things enter or leave• Made of Phospholipid Bilayer

– Made of lipids & proteins – Double layer

Analogy: Main gate/security booth

phospholipid

cell membrane

CYTOPLASMFunction: Prevents cell from collapsing

Facts:– fluid inside the membrane– made of water, sugar, protein, etc.– “framework” called a cytoskeleton

AnalogyAnalogy: Floor of the Factory

cytoskeleton

cytoplasm

NUCLEUS

Function: Stores genetic information (DNA)

Facts:•most but not all cells have a nucleus

Analogy: CEO/Boss of the factory

ChromatinFunction: Is the Genetic information

FACTS:

• Made of Nucleic Acids

• Unorganized form of DNA

• Becomes Chromosomes during cell division

Analogy: Blueprints for the cell phones

RibosomesRibosomes

Function: makes proteins

Facts:

―found on rough ER

Analogy: factory workers who build the cell phones

Endoplasmic Reticulum Endoplasmic Reticulum (ER)(ER)Function: passageway for

supplies to move about the cell

Facts: • Also makes lipids & carbs

Analogy: Assembly line

Golgi apparatusGolgi apparatusFunction: prepares proteins and

other molecules for shipping outside of the cell.

Facts: ― The more molecules a cell makes

the bigger the Golgi

Analogy: packaging center for cell phones

MitochondriaMitochondriaFunction: makes energy for cells

Facts: changes Glucose from food into fuel called ATP

Analogy: generator for factory

LysosomesLysosomesFunction: digests old cell parts

Facts:

–Filled with enzymes that break down large molecules

–Only in animal cells

Analogy: Janitors

CentriolesCentriolesFunction: move and organize chromosomes

during cell division

Facts:–Only in animal cells

Analogy: filing cabinet for blueprints

ChloroplastChloroplastFunction: makes energy for

plant cells

Facts:– Site of photosynthesis

– Uses sunlight to change water & Carbon Dioxide into Glucose and Oxygen

Analogy: solar panels

CELL WALLCELL WALLFunction: Gives structure & support to

plant cells

Facts: – helps plant to grow upright (stiff)

– Is outside the membrane

– In bacteria and plant cells

Analogy: Factory building wall

VACUOLEVACUOLEFunction: Stores water & nutrients

Facts: - Large and in the center in plant cells

- Many small ones in animal cells

– keeps plants from drying out

Analogy: Break room Refrigerator

VESSICLEVESSICLE

Facts:

- Made from cell membrane

-Don’t live very long

-Get recycled

-Analogy: Plastic grocery bags

Function: carries materials around the cell

The DifferencesANIMAL CELL

• Roundish– Lysosomes– Centrioles

PLANT CELL

• Squarish– Chloroplast– Cell Wall– Central Vacuole

Cell energy

• All nutrients must be broken down to GLUCOSE.

• Breakdown of nutrients to glucose is done by enzymes

Make glucose through Photosynthesis

Release energy from glucose Release energy from glucose through cellular respiration through cellular respiration

and ATP Productionand ATP Production

Get glucose from food

WHERE: ChloroplastWHO: plant cellsWHY: turns water and carbon

dioxide into glucose and oxygen!

WHEN: in the presences of light energy (sun)

1.1. LightLight is absorbed by chlorophyll

2. Light splits watersplits water into H2 and O

3. Energy from this split is used to make ATPATP

“Calvin Cycle”

Steps1.Energy from ATP used to make sugarsugar

(C6H12O6) from H2O & CO2

2.Oxygen is “leftover”

Light energy + 6 CO2 + 6 H2O C6H12O6 + 6O2

GLUCOSEGLUCOSE( Monosaccharide sugar)

6 CO26H2OReactants

Products C6H12O6 6O2

Where did they Go?Where did they Go?

The Big Picture

Cell Respiration WHERE: MITOCHONDRIA

WHO: All Eukaryotic Cells

WHY: to turn sugar (glucose) into fuel (ATP)

CC66HH1212OO66+ 6 O+ 6 O22 6 CO 6 CO2 2 + 6 H+ 6 H22OO

and 36 ATPand 36 ATP

carbon dioxide & water are “leftovers”

Two TypesAerobic• Most Eukaryotic

cells

• needs oxygen

• makes 36 ATP

• 3 steps

Fermentation• Yeast & Bacteria• If oxygen isn’t available• only makes 2 ATP

– (ok for small things)

• This is how we make bread, yogurt, beer wine!

It’s a 3 STEP PROCESS

Why: to slowly release energy without heating up the cell too much!

1. Glycolysis: Happens in the cytoplasm to break down glucose

– All living things do glycolysis

2. Krebs Cycle: In the mitochondria, makes a few ATP (not efficient)

3. Electron Transport: In the mitochondria, makes a lot of ATP

The Big Picture1. All nutrients must be

broken down to Glucose

2. Glucose must be converted to ATP

ANALOGY:

Money Tokens

• The main energy molecule in organisms

• Energy is held in the Chemical Bonds

– Breaking a bond releases energy

• ATPADP

– Making a bond stores energy

• ADP ATP

Cellular Energy in the form of ATP gets used to drive cell

processes

EX: Cell Division

Cell Transport

Several items make Cell Transport possible

1. The Phospholipids ( Cell Membrane)

2. A Concentration Gradient

3. Selective Permeability

4. Membrane Bound Proteins

Selectively Permeability: A property of biological membranes that allows some substances to cross the membrane more easily than others.

Concentration gradient: The difference in the amount of solution on each side of a cell membrane

The Phospholipid

HEAD: LOVES WATER hydrophilic

TAIL: HATES WATER hydrophobic

Hydro: Water

Philia: Love

Phobia: Fear or hate

Heads out, tails in… Heads out, tails in…

the membrane forms a bi-layer (2)the membrane forms a bi-layer (2)

Types of Cellular Types of Cellular TransportTransport

Passive Transport– Diffusion– Facilitated Diffusion

• Need Channel Proteins• No ATP

Active Transport– Needs Carrier Proteins– Requires ATP

• Endocytosis• Exocytosis

Passive transportDiffusion: The tendency of a substance to move

from an area of high conc. to an area of low conc. across a membrane in which the cell expends no energy.

(sliding down a slide)

Facilitated Diffusion: the process of transporting molecules by channel proteins during diffusion, requires no energy output

(someone else carrying you down the slide)

Needs: Energy!

Transport of molecules against a concentration gradient (from low conc. to high conc.) using carrier proteins in the cell membrane and energy from ATP.

(walking up the slide)

Active transport

How Does that Look in a Cell?

A:A: Passive Diffusion

B:B: Facilitated Diffusion (needs channel protein)

C:C: Active Transport

(needs ATP & carrier protein)

Types of Active Transport

Exocytosis: The release of materials out of the cell (pooping)

Endocytosis

The taking of materials from outside the cell (eating)

Cell Size and Diffusion• Cells must remain small to maximize diffusion

• The larger a cells volume becomes, the less efficient it becomes.– Prokaryotes - Limited by efficient metabolism– Animal Cells (Eukaryotic) - Limited by surface area

to volume ratio

• Surface area of cells must be proportionally larger than it’s size (volume)

Solvent: a liquid that dissolves the solute, usually water or alcohol Solute: Anything dissolved in a solventTogether they make a Solution

Salt Sucks!Salt Sucks!

When salt is inside or outside the cell, it draws water in its direction.

This is why you get thirsty after eating something salty.

Same thing applies for all other solutes

Solutions and Cells• All solutions want to be equal on both

sides of the membrane for homeostasis.

• Substances dissolved in solution have special vocabulary to describe them

• Hypertonic

• Hypotonic

• Isotonic

Hypertonic

• The conc. of solute outside the cell is higher than the conc. inside

• The solution outside is hypertonic

• Water diffuses out of the cell until equilibrium is established. – The cell will shrink and lose mass

Hypotonic• The conc. of solute outside the

cell is lower than the conc. inside

• The solution outside is hypotonic

• Water diffuses into the cell until equilibrium is established. – The cell will get bigger and gain

mass

Isotonic• The conc. of solute

outside and inside the cell are equal

• The solution outside is isotonic

• Water diffuses into and out at equal rates – No net change in size or

mass

IsotonicHypotonicHypertonic

H2O

CHO

H2O

H2O

H2OH2O

H2O

H2O

H2O

H2O

H2O

H2OH2O

H2OH2O

H2O

CHO

CHO

CHO

CHO

CHO

CHO

CHOCHO

CHOCHO

CHO

CHO

CHO

H2O

H2O

H2OH2O

H2O

H2O

H2O

H2O

H2O

H2O

H2O

H2O

H2O

H2O

•Water moves out

•Cell Shrinks

•Water moves in and out

•Cell Size remains same

•Water moves in

•Cell Swells

Why doesn’t the Glucose (CHO) move into the cell?