Cells notes honors bio

What is a cell? Two types of cells: Prokaryotic vs Eukaryotic

Organelles and their functions The Exception: Viruses Transfer of materials

What is a Cell?

Latin for “small room” Cell theory:

All living things are composed of cellsCells are the basic unit of structure and

function in living thingsNew cells only come from existing cells.

History

1665 Robert Hooke build basic microscope looked at cork dubbed the structures “cells” Latin for

small room1674 Anton Van Leeuwenhoek

saw living cells by observing organisms in pond water.

How big are cells?

http://www.cellsalive.com/howbig.htm

Activity putting items in orderhttp://learn.genetics.utah.edu/content/cel

ls/scale/

Eukaryotic cellsPlants, animals, protists, fungi :

1. Subdivided by internal membranes into different compartments and organelles

2. DNA is enclosed by a membrane-bound nucleus

3. DNA organized into chromosomes

4. Plant cells have a tough cell wall, animal cells do not.

Prokaryotic cells: bacteria

1. Smaller than eukaryotic cells

2. Lack organelles

3. Lack a nucleus - DNA is not separated from the cytoplasm

4. One circular chromosome

5. Tough external walls

Eukaryotic Cell Parts

Cell Membrane

Nucleus Cytoplasm Cell Wall Cytoskeleton

Cell Membrane

Separates inside of cell from surroundings Controls the passage of substances into and out

of the cell “lipid bilayer” made of 2 layers of fats (lipids),

with proteins embedded in it. “selectively-permeable” : some types of

substances (like water) can go through it. Fat layer

Fat layerProtein

Head region of the lipid are polar molecules so they are attracted to water hydrophilic

Tails region of the lipid are nonpolar they repel water. hydrophobic

These molecular properties form the separation of inside and outside the cell.

Cell Wall

In plants, algae, fungi, and prokaryotes (not animals)

Protects cell and is stiff to support the cell (plants don’t need bones their cells are stiff)

Plant cell walls are made of cellulose a non-living material. Plant dies “wood” (cell wall) remains.

Nucleus

Contains DNA which is spread around as chromatin. During reproduction it is wound into chromosomes.

Contains the nucleolus which are involved in making proteins.

Nuclear membrane separates the chromosomes and nucleolus from the cytoplasm and the rest of the cell contains pores

http://tbn1.google.com/images?q=tbn:zvRxwZkGHE07fM:http://content.answers.com/main/content/wp/en/thumb/5/52/300px-Diagram_human_cell_nucleus_no_text.png

Nuclear membrane

Cytoplasm

The material filling the cell inside the cell membrane. It is made mostly of water. Also contains proteins, enzymes, dissolved salts, sugars

Cytoskeleton

A system of tubes inside the cell that helps support it.

Cells Parts

RibosomesGolgi

ApparatusLysosomes

Endoplasmic Reticulum Chloroplasts MitochondriaVacuoles

Ribosomes

“Protein factories” assemble proteins for the cell

•Ribosome•attached to the endoplasmic reticulum

Growing protein

One Ribosome close up

Endoplasmic Reticulum

Rough ER holds ribosomes where proteins are assembled

Smooth ER has no ribosomes and is a place where lipids/cell membrane is made.

http://cache.eb.com/eb/image?id=63513&rendTypeId=4

Golgi Apparatus

Made of a stack of membranesIt attaches carbohydrates and lipids to

proteins Proteins go from ER to Golgi apparatus

to final destination

Vesicles transport proteins and lipids around the cell.

Lysosomes: Contain enzymes to break down materials in the cell

Peroxisomes: break down fatty acids, amino acids, and alcohol

Vacuole

“storage bin”Surrounded by a membrane vacuoles

store liquid/food/waste for the cellPlants often have one large vacuole

http://tbn1.google.com/images?q=tbn:j7oRXNj5R7IArM:http://sun.menloschool.org/~cweaver/cells/c/vacuole/plantcell.gif

Chloroplasts

In plant cells (not animals)

Where photosynthesis happens

Filled with green chlorophyll

Mitochondria

“Powerhouses” of the cellWhere cell respiration happensBreak down glucose to release energy

http://tbn1.google.com/images?q=tbn:zvRxwZkGHE07fM:http://content.answers.com/main/content/wp/en/thumb/5/52/300px-Diagram_human_cell_nucleus_no_text.png

Multicellular organisms have specialized cells

Multicellular versus unicellular

Unicellular organisms are made of a cell that can perform all functions necessary for survival

Multicellular organism have specialized cells that work together for survival

Bacteria

http://www.ted.com/talks/bonnie_bassler_on_how_bacteria_communicate.html Bonnie Bassler: How bacteria "talk“ (18 minutes)

Not cells: Viruses Protein shell with nucleic acid (DNA or RNA)

inside Can’t reproduce by themselves:

Reproduce only in a living cell, damaging cells

Viruses infecting humans include:polio,

Influenza,

herpes,

smallpox,

chickenpox,

& human immunodeficiency virus (HIV) causing AIDS.

Virus reproduction

Injects viral genetic material into living cell.Takes over cell to make copies of itselfCopies burst out of cell.

Animation: http://www.courses.fas.harvard.edu/~biotext/animations/lyticcycle.html

http://www.bbc.com/news/world-africa-26835233 Why Ebola is so dangerous video 1 minute shows virus attaching cell

https://www.youtube.com/watch?v=aM3vhZrNa7E virus infection in a cell 3:13

Fighting Infection

http://videos.howstuffworks.com/science-channel/29783-100-greatest-discoveries-penicillin-video.htm

discovery of antibiotics30 sec video about vaccines and

antibodies http://www.bbc.co.uk/schools/gcsebitesize/science/21c/keeping_healthy/antibiotics_drug_testingrev1.shtml

Specific Immunity, Antibodies https://www.youtube.com/watch?v=Ys_V6FcYD5I

1. What is an antibiotic? 2. What is a antibody? 3. What is a vaccine?

Describe the difference between antibiotics and a vaccine.

Antibiotic resistant bacteria

https://www.youtube.com/watch?v=ycv3bZuZZjA Evolutionary arms race, TB in Russian prisons

http://www.niaid.nih.gov/topics/antimicrobialResistance/Understanding/Pages/mutation.aspx

size

Eukaryotic cells: small

Prokaryotic (bacteria) cells: smaller

Viruses: smallest

Origin of life / Ancient Earth

Formation of the Earth: cosmic dust collected for 100 million years. Liquid Earth, dense materials sank to center (iron

core) Solid crust formed, gases formed atmosphere

Early atmosphere different composition then today: hydrogen cyanide, CO2, CO, Nitrogen, Hydrogen

sulfide and water.

timeline

4 billion years ago Earth’s crust formed 3.8 billion years ago surface cold enough for water to

remain liquid. Ocean’s formed Ocean water brown = of lots of iron. Little Oxygen in

atmosphere 3.5 billion years ago: Single celled organisms 2.3 billion years ago: photosynthetic bacteria in

oceans started adding lots of oxygen to atmosphere 2 billion years ago: eukaryotic cells 1 billion years ago multicellular organisms developed

Miller and Urey’s Experiment 1950’s

Non-living molecules like water and methane forming organic molecules

Amino acids were formed when electricity was passed through inorganic molecules that would have been found in Earth’s early atmosphere.

Mitochondria and chloroplasts

Have different DNA then the nucleus of the cell they are in.

Smaller prokaryotic organisms (became mitochondria) started living in larger prokaryotic organisms (became eukaryotic animal cells.

Smaller prokaryotic organisms (became chloroplasts) started living in larger prokaryotic organisms (became eukaryotic plant cells).

The evolution of the cell

http://learn.genetics.utah.edu/content/cells/organelles/

1. What is the Endosymbiotic theory? The theory is that Mitochondria and chloroplasts were once primitive bacteria cells which inserted themselves in a larger primitive cell and then developed a symbiotic relationship to become an integral part of the cells processes.

The evolution of the cell

2. List the pieces of evidence that support the theory. Mitochondria and chloroplasts have

their own DNA which is separate from the DNA found in a eukaryotic cells nucleus

They have a double membrane like a cellreproduce like bacteria replicating their own

DNA and directing their own division

The evolution of the cell

3. What is the difference between mitochondrial DNA and nuclear DNA? Why is mitochondrial DNA more useful for inheritance studies?Mitochondrial DNA is a copy of the mothers

mitochondrial DNA not a combination of 2 parents.

Mitochondiral DNA is passed directly from mother to child so it does not accumulate changes as fast as nuclear DNA.

organisms became complex because:

Eukaryotic cells started reproducing sexually: sexually (mix of parental DNA) asexually (exact copies)

Cells started coordinating to form multi-cellular organisms.

Protists lab

Kingdom Protista: the protists video segment 7 minutes united streaming

http://www.youtube.com/watch?v=0-6dzU4gOJo 3 minutes dramatic trailer style introduction to protists great microscopy