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CH 3 CH 3 Cells are the smallest units of life

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CH 3CH 3

Cells are the smallest units of life

The Cell Theory1.

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 singleAlways single--

celledcelled••

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 functionsEX: 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

A cell is like a cell phone factory

CELL MEMBRANEFunction: controls what goes in & out & makes

cells waterproofFacts:•

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 collapsingFacts:

fluid

inside the membrane–

made of water, sugar, protein, etc.

“framework”

called a cytoskeleton

AnalogyAnalogy: Floor of the Factorycytoskeleton

cytoplasm

NUCLEUS Function: Stores genetic information (DNA)Facts:

•most but not all cells have a nucleus

Analogy: CEO/Boss of the factory

ChromatinFunction: Hold Genetic information

FACTS: •

Made of Nucleic Acids

Unorganized form of DNA

Becomes Chromosomes during cell division

Analogy: Blueprints for the cell phones

RibosomesRibosomesFunction: makes proteinsFacts:―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 cellsFacts: changes Glucose from food

into fuel called ATP

Analogy: generator for factory

LysosomesLysosomesFunction: digests old cell partsFacts:

–Filled with enzymes that break down large molecules

–Only in animal cellsAnalogy: 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 & nutrientsFacts:

-

Large and in the center in plant cells-

Many small ones in animal cells

– keeps plants from drying out

Analogy: Break room Refrigerator

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 O3. Energy from this split is used to

make ATPATP

“Calvin Cycle”Steps1.Energy from ATP used to make sugarsugar

(C6 H12 O6 ) from H2 O & CO2

2.Oxygen is “leftover”

Light energy + 6 CO2 + 6 H2 O C6 H12 O6 + 6O2

GLUCOSEGLUCOSE

( Monosaccharide sugar)

6 CO2 6H2

OReactants

Products C6

H12

O6

6O2

Where did they Go?Where did they Go?

The Big Picture

Cell RespirationWHERE: MITOCHONDRIAWHO: All Eukaryotic CellsWHY: to turn sugar (glucose) into fuel (ATP)

CC66 HH1212 OO66 + 6 O+ 6 O22 6 CO6 CO2 2 + 6 H+ 6 H22 OO

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 PROCESSWhy: 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 DivisionCell Transport

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)

Several items make Cell Transport possible

1.

The Phospholipids ( Cell Membrane)2.

A Concentration Gradient

3.

Selective Permeability4.

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 inHeads out, Tails in……

the membrane forms a Bithe membrane forms a Bi--layer (2)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)

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 DiffusionB: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)

EndocytosisThe taking of materials from outside the cell (eating)

Solvent: a liquid that dissolves the solute, usually water or alcohol

Solute:

Anything dissolved in a solvent

Together 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 other all solutes

Solutions and Cells•

All substances 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

CHO

H2 O

CHOH2 O

H2 O

H2 OH2 O

H2 O

H2 O

H2 O

H2 O

H2 O

H2 OH2 O

H2 OH2 O

H2 O

CHO

CHO

CHO

CHO

CHO

CHOCHO

CHOCHO

CHO

CHO

CHO

H2 O

H2 O

H2 OH2 O

H2 O

H2 O

H2 O

H2 O

H2 O

H2 O

H2 O

H2 O

H2 O

H2 O

•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?