CellsCells

Cells could not be seen without a microscope Cells could not be seen without a microscope before the 17before the 17thth century. century.

Leeuwenhoek made the first microscope.Leeuwenhoek made the first microscope. Hooke named “cells” while looking at cork.Hooke named “cells” while looking at cork. 1838 – Schleiden - plants are made of cells1838 – Schleiden - plants are made of cells 1839 – Schwann – animals are made of cells and 1839 – Schwann – animals are made of cells and

there is a cellular basis of all life.there is a cellular basis of all life. 1855 – Virchow – animal comes from animal and 1855 – Virchow – animal comes from animal and

plant comes from plantplant comes from plant

Cell TheoryCell Theory

1.1. Cells are the basic units of lifeCells are the basic units of life

2.2. All organisms are made of one or more All organisms are made of one or more cellscells

3.3. Cells arise from other cellsCells arise from other cells

Cell MembraneCell Membrane

Cell membraneCell membrane – gate, controlling what – gate, controlling what comes in and out of the cellscomes in and out of the cells

• Phospholipid bilayerPhospholipid bilayer – phosphate head – phosphate head and two fatty acid tailsand two fatty acid tails

• Phosphate headPhosphate head – – hydrophilichydrophilic (water (water loving)loving)

• Fatty tailsFatty tails – – hydrophobichydrophobic (water hating) (water hating)

Cell Membrane (cont.)Cell Membrane (cont.)

Many proteins Many proteins embedded in the embedded in the membranemembrane

1.1. Integral proteins - Integral proteins - amphipathicamphipathic

2.2. Peripheral proteins – Peripheral proteins – loose connectionloose connection

3.3. Carbohydrate side Carbohydrate side chainschains

4.4. Cholesterol – membrane Cholesterol – membrane fluidityfluidity

1.1. Recognition proteinsRecognition proteins – identify the cell – identify the cell

2.2. Channel proteinsChannel proteins – let things in and out of – let things in and out of the cellthe cell

3.3. Adhesion proteins Adhesion proteins – form junctions with – form junctions with other cellsother cells

4.4. Transport pumps Transport pumps – sodium/potassium – sodium/potassium pumppump

5.5. Receptor proteins Receptor proteins – G-protein linked– G-protein linked

Prokaryote Cell – Bacterial CellsProkaryote Cell – Bacterial Cells

Animal CellAnimal Cell

NucleusNucleus

The control center – The control center – “brain”“brain”

Nuclear envelopeNuclear envelope – – covered in pores – send covered in pores – send proteins outproteins out

Contains DNA Contains DNA DNA coils into DNA coils into chromatinchromatin

and chromatin condenses and chromatin condenses into into chromosomeschromosomes (blueprint)(blueprint)

NucleolusNucleolus

Dark structure inside the nucleusDark structure inside the nucleus Make Make ribosomesribosomes Disappears during Disappears during mitosis mitosis (cell division)(cell division)

Prokaryote vs. EukaryoteProkaryote vs. Eukaryote

Prokaryotes Prokaryotes – bacterial cells– bacterial cells• Do not have a nucleusDo not have a nucleus• Have fewer partsHave fewer parts• Have DNA and reproduceHave DNA and reproduce• No membrane around organellesNo membrane around organelles

Eukaryotes Eukaryotes – plants, animals– plants, animals• Have a nucleusHave a nucleus• Have more partsHave more parts• Membrane bound organellesMembrane bound organelles

CytoplasmCytoplasm

CytosolCytosol and organelles and organelles Cytosol is mostly waterCytosol is mostly water OrganellesOrganelles – nucleus and other parts – nucleus and other parts

floating in cytosolfloating in cytosol

OrganellesOrganelles

RibosomesRibosomes – On the – On the rough endoplasmic rough endoplasmic reticulum and free in reticulum and free in the cytoplasmthe cytoplasm make proteins make proteins

(manufacturer)(manufacturer)

Smooth endoplasmic Smooth endoplasmic reticulumreticulum detoxification and detoxification and

making lipids and making lipids and carbohydratescarbohydrates

Golgi and LysosomesGolgi and Lysosomes

Golgi apparatusGolgi apparatus stack of pancakesstack of pancakes Packages things and Packages things and

sends them out of the sends them out of the cellcell

LysosomeLysosome digestion of food digestion of food

particlesparticles contain enzymes contain enzymes

MitochondriaMitochondria

Powerhouse of the cellPowerhouse of the cell ATP – energy is ATP – energy is

createdcreated

Cell ShapeCell Shape

CytoskeletonCytoskeleton – internal – internal framework in an animal cell framework in an animal cell that helps maintain cell that helps maintain cell shape.shape.

MicrotubulesMicrotubules – hollow tubes – hollow tubes made of protein - help made of protein - help maintain cell shape and maintain cell shape and serve as tracks for transport serve as tracks for transport throughout the cell.throughout the cell.

Cillia and FlagellaCillia and Flagella are made are made of microtubules.of microtubules.

Microfilaments Microfilaments – smaller – smaller proteins that help maintain proteins that help maintain cell shape. cell shape.

EuglenaEuglena

ParameciumParamecium

Plant CellsPlant Cells

Plant cells have a Plant cells have a cell wallcell wall – made of – made of cellulosecellulose

They also have They also have chloroplastschloroplasts – where – where photosynthesis occursphotosynthesis occurs

ChlorophyllChlorophyll – pigment that absorbs sunlight – pigment that absorbs sunlight energyenergy

VacuolesVacuoles – large vacuole that stores water – large vacuole that stores water

Plant CellsPlant Cells

Cell DifferencesCell Differences

Know table on pg. 40Know table on pg. 40