What do these organisms have

in common?

CELLS

CR E AT ED BY:

A SH L E Y RE I D

H E ATH ER WAT SON

M I CHAE L A

CH E E

WHAT WE WILL BE COVERING

What is a cell?The types of cells

Examples of these cellsThe organelles and their

functions

WHAT IS A CELL?• Latin for “small room”• A cell is the functional and

structural unit of all living organisms

CELL THEORY• The cell is the basic unit of

structure• Conducts all functions for

living organisms• All cells arise from pre-

existing cells

EXAMPLES OF CELLSAmoeba Proteus

Plant Stem

Red Blood Cell

Nerve Cell

Bacteria

PLANT & ANIMAL CELLSsimilarities & differences

Plant Animal

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

PLANT CELLS• Has a cell wall

made of cellulose• Has a large

central vacuole• Undergoes

photosynthesis• Contains

chloroplasts which contain chlorophyll

CELL WALL• One of the most importantdistinguishing features of plant cellsis the presence of a cell wall, whichserves a variety of functions.• The cell wall protects the cellular contents and gives rigidity structure to the plant• Provides a porous medium for the circulation

and distribution of water, minerals, and other small nutrient molecules

• Contains specialized molecules that regulate growth and protect  the plant from disease

ANIMAL CELLS• Unicellular &

multicellular • Lacks a cell wall

and chloroplasts • Small vacuoles• Appear spherical

in shape• Contains a

variety of organelles

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

• Double layer • Serves as a

boundary between the cell and its external environment

• Found in plant & animal cells

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

DIFFUSION• Diffusion is “the movement of a

substance from a region of higher concentration to a region of lower concentration” (Mader, 1994)• Diffusion always moves from an area of

high concentration to an area of low concentration• It’s the way materials such as gasses

(oxygen) and liquids (water) move across the cell membrane• Occurs in plant and animal cells

OSMOSIS• Movement of water (h2o) molecules

across a semi permeable membrane from an area of high concentration to low concentration

• Water molecules will move toward a high concentration of solute (low concentration of water) to reach equilibrium

• Important process because all living organisms are composed of mostly water, osmosis allows water

to travel through different parts of the body to reach areas that need it to function• Occurs in plant and animal cells

CHLOROPLASTS• They contain chlorophyll which is the green pigment used to make food• Photosynthesis takes place in the chloroplasts• They use light energy from the sun, water, and

carbon dioxide in order to create sugars and oxygen

• Plants, animals, & humans use sugars for food & energy

• Humans and animals use the oxygen to breathe• Found only in plant cells

CYTOPLASM• Jelly-like fluid within the cell membrane• Composed primarily of water• It’s the substance that a cell’s organelles are

embedded in• Different molecules are dissolved in the

cytoplasm such as …• Enzymes, fatty acids, sugars & amino acids

which all keep the cell functioning• Waste is dissolved in the cytoplasm before

taken in by the vacuoles or being sent out of the cell

• Found in plant and animal cells

VACUOLES• Organelles that are primarily

used for storage• Vacuoles can store water,

waste products, and other substances

• Plant cells have much larger vacuoles than animal cells• Found in plant & animal cells

NUCLEUS• Often referred to as the

control center of the cell• Stores DNA & controls cell activity• Found in plant & animal cells

MITOCHONDRIA• Where energy is made, which is used to fuel cell• Site where cellular respiration takes place• Cellular respiration isthe opposite process ofphotosynthesis in which livingorganisms take in oxygen andsugars in order to give off carbon dioxide, water, & energy

• There can be one or many mitochondria in a cell• Found in plant & animal cells

CELL ACTIVITY• Split into two groups• One group will construct an animal cell & the other will construct a plant cell• Animal cell group needs the bowl of orange jello• Plant cell group needs the bowl of green jello• Use any of the objects provided to represent

organelles in your group’s cell• Be prepared to present your group’s cell & why

you chose those objects• REMEMBER – animal & plant cells have some

similarities & differences!

REFERENCESDavidson, M. (2004, December 13). Molecular expressions biology and microscopy structure

and function of cells and viruses mitochondria. Retrieved from

http://micro.magnet.fsu.edu/cells/mitochondria/mitochondria.html

Davidson, M. (2005, May 14). Molecular expressions biology and microscopy structure and

function of cells and viruses nucleus. Retrieved from http://micro.magnet.fsu.edu

/cells/nucleus/nucleus.html

Mader, S. (1994). Inquiry into Life (7th ed). Dubuque, Iowa: W. C. Brown Publishers

(Part Two, pp 42-119)

Traverso, M. (2004, August 08). Washington university in st. louis chemistry 152 diffusion and

concentration gradients. Retrieved from http://www.chemistry.wustl.edu/~courses

/genchem/Tutorials/Kidney/dynamic.htm

ACTIVITY #2