Cells are the smallest units of life CH 3 CELLS

The Cell Theory All living things are composed of one or more cells. Cells are the basic units of structure and function. Cells are produced only from existing cells.

All living things have cells Unicellular creatures have 1 cell Multicellular creatures have 2 or more cells

Cell Types

Prokaryotic (Pre) ( Nucleus) Always single- celled lacks organelles Few specialized functions Bacteria are the only group of organisms that are prokaryotic!!!

Eukaryotic (True) ( 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

Which type of cell is this one? Prokaryotic! Which type of cell is this one?

Which type is this one?

What do you think these cells are? skin cells CELLS: What do you think these cells are? fat cells Nerve cell Egg cell with sperm surrounding it muscle cells plant cells

little “organs” that have Cell Organelles little “organs” that have specific jobs in a cell                      

The Differences ANIMAL CELL PLANT CELL Roundish Squarish Lysosomes Centrioles PLANT CELL Squarish Chloroplast Cell Wall Central Vacuole 11

A cell is like a cell phone factory

CELL MEMBRANE Function: 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

CYTOPLASM Facts: Function: Prevents cell from collapsing fluid inside the membrane made of water, sugar, protein, etc. “framework” called a cytoskeleton Analogy: 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

Chromatin Function: Is the Genetic information FACTS: Made of Nucleic Acids Unorganized form of DNA Becomes Chromosomes during cell division Analogy: Blueprints for the cell phones

Ribosomes found on rough ER Function: makes proteins Facts: found on rough ER Analogy: factory workers who build the cell phones

Endoplasmic Reticulum (ER) Function: passageway for supplies to move about the cell Facts: Also makes lipids & carbs Analogy: Assembly line

Golgi apparatus Function: 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

Mitochondria Function: makes energy for cells Facts: changes Glucose from food into fuel called ATP Analogy: generator for factory

Lysosomes Function: digests old cell parts Facts: Filled with enzymes that break down large molecules Only in animal cells Analogy: Janitors

Centrioles Function: move and organize chromosomes during cell division Facts: Only in animal cells Analogy: filing cabinet for blueprints

Chloroplast Function: makes energy for plant cells Facts: Site of photosynthesis Uses sunlight to change water & Carbon Dioxide into Glucose and Oxygen Analogy: solar panels Only in Plant Cells

CELL WALL Function: 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

VACUOLE Function: 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

VESSICLE Facts: - Made from cell membrane Function: carries materials around the cell Facts: - Made from cell membrane -Don’t live very long -Get recycled Analogy: Plastic grocery bags 26

The Differences ANIMAL CELL PLANT CELL Roundish Squarish 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

Plants Animals Make glucose through Photosynthesis Get glucose from food Release energy from glucose through cellular respiration and ATP Production

Photosynthesis WHERE: Chloroplast WHO: plant cells WHY: turns water and carbon dioxide into glucose and oxygen! WHEN: in the presences of light energy (sun)

Light Dependent Reactions Light is absorbed by chlorophyll Light splits water into H2 and O Energy from this split is used to make ATP

Dark Reactions “Calvin Cycle” Steps Energy from ATP used to make sugar (C6H12O6) from H2O & CO2 Oxygen is “leftover”

( Monosaccharide sugar) Equation Light energy + 6 CO2 + 6 H2O C6H12O6 + 6O2 GLUCOSE ( Monosaccharide sugar)

Where did they Go? 6H2O Reactants 6 CO2 Products C6H12O6 6O2

The Big Picture

Cell Respiration WHERE: MITOCHONDRIA WHO: All Eukaryotic Cells WHY: to turn sugar (glucose) into fuel (ATP)

carbon dioxide & water are “leftovers” Equation C6H12O6+ 6 O2  6 CO2 + 6 H2O and 36 ATP carbon dioxide & water are “leftovers”

Two Types Aerobic Fermentation 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! Glycolysis: Happens in the cytoplasm to break down glucose All living things do glycolysis Krebs Cycle: In the mitochondria, makes a few ATP (not efficient) Electron Transport: In the mitochondria, makes a lot of ATP

ATP denosine ri- hosphate

The Big Picture All nutrients must be broken down to Glucose Glucose must be converted to ATP ANALOGY: Money  Tokens

Adenosine Triphosphate The main energy molecule in organisms Energy is held in the Chemical Bonds Breaking a bond releases energy ATPADP Making a bond stores energy ADP ATP

ATP Energy from food Energy for Cells ADP

Cellular Energy in the form of ATP gets used to drive cell processes EX: Cell Division Cell Transport

Cell Transport

Several items make Cell Transport possible The Phospholipids ( Cell Membrane) A Concentration Gradient Selective Permeability 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 membrane forms a bi-layer (2) The Phospholipid Hydro: Water Philia: Love Phobia: Fear or hate HEAD: LOVES WATER hydrophilic TAIL: HATES WATER hydrophobic Heads out, tails in… the membrane forms a bi-layer (2)

Types of Cellular Transport Passive Transport Diffusion Facilitated Diffusion Need Channel Proteins No ATP Active Transport Needs Carrier Proteins Requires ATP Endocytosis Exocytosis

Passive transport Help + = Diffusion: 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) + Help =

Active transport 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)

How Does that Look in a Cell? A: Passive Diffusion B: Facilitated Diffusion (needs channel protein) C: Active Transport (needs ATP & carrier protein)

Types of Active Transport Endocytosis The taking of materials from outside the cell (eating) Exocytosis: The release of materials out of the cell (pooping)

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 solvent Together they make a Solution Salt Water + =

This is why you get thirsty after eating something salty. A simple rule: 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

Why doesn’t the Glucose (CHO) move into the cell? Isotonic Hypotonic Hypertonic H2O CHO Water moves out Cell Shrinks Water moves in Cell Swells Water moves in and out Cell Size remains same Why doesn’t the Glucose (CHO) move into the cell?