Agenda: Sept 22nd

• Review for Test (tomorrow)– Cell Structure and Function – Types of Cells– Cell’s molecules

• Measuring Very Small Volumes with a Micropipet – Basics– Prepare for Lab after test

Study for Cell Test!Tables

Inside the Cell

Cell Structure & Function

http://koning.ecsu.ctstateu.edu/cell/cell.html

Eurkaryotic Cell (Eukaryote)

Cell Video

Cell Theory

• All living things are made up of cells.

• Cells are the smallest working units of all living things.

• All cells come from preexisting cells through cell division.

Links

• Animation: Center of the cell

• Centre of the Cell

• Cell Biology Animation

• cell structure

Definition of Cell

A cell is the smallest unit that is capable of performing life

functions.

Examples of Cells

Amoeba Proteus

Plant Stem

Red Blood Cell

Nerve Cell

Bacteria

Two Types of Cells

•Prokaryotic–Bacteria

•Eukaryotic–Animal–Plant–Yeast (fungus)

Prokaryotic

• Do not have structures surrounded by membranes

• Few internal structures

• One-celled organisms, Bacteria

http://library.thinkquest.org/C004535/prokaryotic_cells.html

Typical Bacterial Cell

Eukaryotic• Contain organelles surrounded by membranes• Most living organisms

Plant Animal

http://library.thinkquest.org/C004535/eukaryotic_cells.html

“Typical” Animal Cell

http://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif

http://waynesword.palomar.edu/images/plant3.gif

“Typical” Plant Cell

Yeast Cell

Cell Parts

Organelles

Surrounding the Cell

Cell Membrane

• Outer membrane of cell that controls movement in and out of the cell

• Double layer

http://library.thinkquest.org/12413/structures.html

Cell Wall

• Most commonly found in plant cells & bacteria

• Supports & protects cells

http://library.thinkquest.org/12413/structures.html

Inside the Cell

Nucleus

• Directs cell activities

• Separated from cytoplasm by nuclear membrane

• Contains genetic material - DNA

Nuclear Membrane

• Surrounds nucleus• Made of two layers• Openings allow

material to enter and leave nucleus

http://library.thinkquest.org/12413/structures.html

Chromosomes

• In nucleus• Made of DNA• Contain instructions

for traits & characteristics

http://library.thinkquest.org/12413/structures.html

Nucleolus

• Inside nucleus• Contains RNA to build

proteins

http://library.thinkquest.org/12413/structures.html

Cytoplasm

• Gel-like mixture

• Surrounded by cell membrane

• Contains hereditary material

Endoplasmic Reticulum• Moves materials around

in cell• Smooth type: lacks

ribosomes• Rough type (pictured):

ribosomes embedded in surface

http://library.thinkquest.org/12413/structures.html

Ribosomes

• Each cell contains thousands

• Make proteins• Found on

endoplasmic reticulum (ER) & floating throughout the cell

http://library.thinkquest.org/12413/structures.html

Mitochondria

• Produces energy through chemical reactions – breaking down fats & carbohydrates

• Controls level of water and other materials in cell

• Recycles and decomposes proteins, fats, and carbohydrates

http://library.thinkquest.org/12413/structures.html

Golgi Bodies

• Protein 'packaging plant'

• Move materials within the cell

• Move materials out of the cell

http://library.thinkquest.org/12413/structures.html

Lysosome• Digestive 'plant' for

proteins, fats, and carbohydrates

• Transports undigested material to cell membrane for removal

• Cell breaks down if lysosome explodes

http://library.thinkquest.org/12413/structures.html

Vacuoles

• Membrane-bound sacs for storage, digestion, and waste removal

• Contains water solution

• Help plants maintain shape

http://library.thinkquest.org/12413/structures.html

Chloroplast

• Usually found in plant cells

• Contains green chlorophyll

• Where photosynthesis takes place

http://library.thinkquest.org/12413/structures.html

Structure Membrane-bound?

Plants, animals or both?

Function

Nucleus Yes Both Houses chromosomes

Smooth endoplasmic reticulum (SER)

Yes Both Lipid synthesis

Rough endoplasmic reticulum (RER)

Yes Both Protein synthesis

Golgi complex Yes Both Sorts contents from the ER and routes them to their appropriate locations

Lysosomes Yes Both Contain digestive enzymes that break down items that the cell doesn’t need

Central vacuole Yes Plants Storage of water and nutrients

Chloroplasts Yes Plants Photosynthesis

Mitochondria Yes Both Energy producer - ATPAerobic cellular respiration

Structure Membrane-bound?

Plants, animals or both?

Function

Cell membrane No Both Outer boundary of the cell

Ribosomes No Both Protein synthesis

Cytoplasm No Both Liquid portion of the cell

Cell wall No Plants A rigid layer on the surface of the cell membrane – Not the same structure as bacteria!

Flagella No Animals (MAYBE)

A “tail”

Cytoskeleton No Both A series of fibers that runs through the cell. Used to support the shape of the cell, for reproduction, and for tracks for other organelles to move along in the cell

Cilia No Only found on certain types of cells – not a standard structure

Microscopic “hairs” on the cell surface

Typical Animal Cell

Human Cell

Typical Plant Cell

Plant Cells

Yeast

Eukaryotic Cell

(Fungus)

Yeast reproduce by budding

Prokaryotic Cells: Required Structures

Structure Function

Cell (plasma) membrane Outer boundary of the cell

Nucleoid Area where single loop of DNA is located

Ribosomes Produces proteins

Cytoplasm Liquid portion of the cell

Bacteria- Some Optional StructuresStructure Function

Cell wall An extra layer (usually made of peptidoglycan) on the surface of the cell

Flagellum (a) A “tail”

Capsule A gooey layer of the surface of the cell

Pili Microscopic “hairs” on the bacterial cell surface

Plasmid An extra loop of DNA

Endospores Bacterial cells can convert themselves to spores as a survival strategy

Typical Bacterial Cell

Microscopic View of Bacteria

Genome Size

• The total genome size differ quite considerably in different organisms.

Organism Number of Chromosomes Genome size in base pairs

• Bacteria 1 ~400,000 - ~10,000,000

• Yeast 12 14,000,000• Worm 6 100,000,000• Fly 4 300,000,000• Weed 5 125,000,000• Human 23 3,000,000,000

OrganismThe number of predicted genes

Part of the genome that encodes proteins (exons)

E.Coli (bacteria) 5000 90%

Yeast 6000 70%

Worm 18,000 27%

Fly 14,000 20%

Weed 25,500 20%

Human 30,000 < 5%

Genes & % of DNA