Cells

What is a cell?• A cell is the smallest functional unit

of life (it is the smallest, most simple thing that can still be considered living)

• It is basis for “organization”

Structural OrganizationOrganism

Organ System

Organ

Tissue

Cell

The Invention of the Microscope

• Antonie van Leeuwenhoek–Mid 1600s–Made 1st microscope–Magnification of 270x–Observed pond water

Who discovered the cell?• 1665 Robert Hooke used a microscope

to look at cork. The cork looked like little boxes under the microscope.

• Fun fact: Hooke used the word “cells” because the boxes he saw under the microscope reminded him of cells that monks lived in.

This is what cells look like under a microscope

Who discovered the cell?• 1830s Matthias Schleiden determines that

all plants are made up of cells. Theodor Schwann determines all animals are made up of cells.

• 1855 Rudolf Virchow says that all cells must come from other cells.

• This all lead up to The Cell Theory

Cell Theory• The cell theory has 3 parts:

1. All living things are made up of cells.2. The cell is the basic organizational

unit of all living things.3. Cells must come from other cells.

The Parts of a Cell• Nucleus• Mitochondria• Golgi apparatus• Endoplasmic Reticulum• Ribosomes• Vacuoles• Cell membrane• Cytoplasm

Organelles

Organelles•Cell parts = organelles

Nucleus• The “brain” of the cell• Directs cell activities• Where genetic information is stored

–DNA Genes ChromosomesNucleus

Mitochondria• The “powerhouse” of the cell• Releases energy for the cell to use

Mitochondria

Ribosomes• Make protein

Ribosomes

Vacuoles• Used for storage• Like containers that you use to store

leftovers in the fridgeVacuole

Endoplasmic Reticulum• Folds the proteins• Processes (modifies) proteins

Smooth Endoplasmic

Reticulum

Rough Endoplasmic

Reticulum

Golgi Bodies• Packages proteins (and other materials)

into vesicles so they can be “shipped” to other parts of the cell

Golgi Bodies

Cytoplasm• Like gelatin• Surrounds all of the organelles• Can also be called the cytoskeleton

Cytoplasm

Cell membrane• The covering of the cell• Allows certain materials to enter or

leave the cell.Cell

Membrane

There are 2 types of cells

•Prokaryotic•Eukaryotic

Prokaryotic• 1st kind of cell• Very simple• No internal organelles (except

ribosomes)• All bacteria fit into this category

Eukaryotic• Last to evolve• More complex• Have organelles• 2 types of eukaryotic cells

–Plant cells–Animal cells

Organelles Only Found in Plant Cells

• Cell wall• Chloroplast

ChloroplastCell Wall

Cell Wall• Plants don’t have skeletons to hold

them up, so each cell has a thick cell wall that provides support.

• Cell wall contains cellulose• This is what you hear snapping/crunching

when you chew lettuce or raw green beans.

Humans don’t have chloroplasts. If they did, they

would be green!

Chloroplast• Chloroplasts contain chlorophyll• Chlorophyll is a pigment that traps

sunlight• This is the part of the plant that converts

sunlight to chemical energy in a process called photosynthesis.

Common Plant and Animal Cell Organelles

Animal Cell Plant Cell

Cell Membrane

Nucleus

Ribosome

Golgi Body

VacuoleSmooth Endoplasmic ReticulumRough Endoplasmic Reticulum

Mitochondrion

Common Plant and Animal Cell Organelles

Animal Cell Plant Cell

Differences Between Plant and Animal CellsCell Wall

Chloroplast

Larger Vacuole

Plant CellAnimal Cell

Are All Cells the Same Shape?

Are All Cells the Same Shape?

• No! • Each cell has a different shape

that fits what its job is.

Are All Cells the Same Shape?

Each cell has a different shape that fits what its job is.

Metabolism• Metabolism is how fast a cell can get materials

in, break them down and build new stuff out of it…

–Anabolism• cells building things (like protein)

–Catabolism• cells breaking things down (the food you eat)

• Anabolism + Catabolism = Metabolism

Review Time!

Let’s see what you learned today…

Compare and Contrast the Organelles Found in Plant Cells Vs. Animal Cells

PlantsAnimals

Both

Compare and Contrast the Organelles Found in Plant Cells Vs. Animal Cells

PlantsAnimals

Both Cell WallChloroplastsNucleus

ERGolgi BodyMitochondriaRibosomesVacuolesCell membrane

How Do Cells Play a Role in Structural Organization?

How Do Cells Play a Role in Structural Organization?

Organism

Organ System

Organ

Tissue

Cell

Why do plant cells need a larger vacuole than animal

cells?

Why do plant cells need a larger vacuole than animal cells?

Because plants make their own food from sunlight. Sunlight is not available 24-7, so the plant has to be able to store lots of food in case it does not get sunlight for awhile.

Is this a prokaryotic or a eukaryotic cell?

Cell Membrane

Cell Wall

Large Vacuole

Chloroplast

Is this a prokaryotic or a eukaryotic cell?

Cell Membrane

Cell Wall

Large Vacuole

Chloroplast

Eukaryotic cell – it has organelles

Is E. coil bacteria a prokaryotic cell or a eukaryotic cell?

Is E. coil bacteria a prokaryotic cell or a eukaryotic cell?

Prokaryotic– it has no

organelles

What type of cell is this?

Cell Membrane

Cell Wall

Large Vacuole

Chloroplast

What type of cell is this?

Cell Membrane

Cell Wall

Large Vacuole

Chloroplast

PLANT CELL

Can you tell what each organelle does?

• Nucleus- • Ribosome-• Chloroplast-• Mitochondria-• Endoplasmic Reticulum-• Vacuole-• Golgi Apparatus-

Can you tell what each organelle does?

• Nucleus- controls the cell’s activities• Ribosome- makes protein• Chloroplast- makes sunlight into food• Mitochondria- makes energy• Endoplasmic Reticulum- folds proteins• Vacuole- stores stuff• Golgi Apparatus- packages and ships stuff