LIST THE 8 CHARACTERISTICS OF LIFE

Warm Up 9-12-2014

Cell Structure and Function Notes

Discovery of the Cell: • Mid 1600’s scientists began using

microscopes to observe living things

• Robert Hooke used microscope to observe thin slice of cork—dead plant materialCork seemed to be made of box-like chambers—Hooke called cells

• Anton van Leeuwenhoek discovered living cells in pond water

Cell Theory:• All living things composed of cells

• Cells are the basic unit of structure and function in living things

• New cells are produced from existing cells

Cell and its Environment:

• Organisms made of one cell—unicellular organisms

Ex: bacteria

• Organisms made of many cells—multicellular organisms

Ex: plants, animals

• Each cell must be in “balance” with its environment, exchange food, waste, H2O, CO2, O2 etc.

• Process by which organisms maintain a relatively stable internal environment—homeostasis

Cell:

• Organisms that do not have a distinct nucleus—prokaryotic (PRO = NO)

Ex: bacteria

• Organisms with cells that have true nucleus and organelles—eukaryotic (EU = TRUE)

Ex: plants, animals, fungi

Cell Parts and Their Functions:

Specialized cell parts called organelles—“little organs”

Cell membrane—determines what goes in and out of the cell aka “gate keeper”

Cytoplasm—gel-like medium that holds the organelles in position

1. Nucleus—control center of the cell• Double membrane that surrounds the nucleus—

nuclear membrane

• Hereditary information inside the nucleus—chromatin (DNA)

Structure Prokaryotic,

Eukaryotic, or Both?

Plant, Animal, or Both

General Characteristics and Functions

Nucleus

Eukaryotic

Both

Control center of the cell. Contains genes that control cell activities. Contains most of the cell's DNA, which is stored as chromatin (DNA wrapped in protein).

Small, dense region in the nucleus. Involved in the synthesis of ribosomes which are important in protein synthesis. "Little nucleus" Double membrane, each consisting of a phospholipid bilayer. Perforated by nuclear pores which allow RNA molecules to leave the nucleus.

4. Ribosomes—makes proteins

RIBOSOMES

• Tiny, granular organelles located on _endoplasmic reticulum_____ or suspended in _cytosol_______. Site of _protein production_____. All cells (pro & euk) have ribosomes.

5. Rough Endoplasmic Reticulum (rough ER)— makes and transports proteins within the cell

• Called rough ER because of the ribosomes found on its surface

Rough ERExtensive network continuous with _nuclear envelope_____. Called “rough” because it has _ribosomes___ all along the membrane. Function of the rough ER is to _modify & transport proteins_____. Most of these proteins are packaged into _vesicles______ (like bubbles or sacs) and shuttled to the __Golgi apparatus________

6. Smooth Endoplasmic Reticulum (smooth ER)—manufactures and transport lipids and other materials within the cell. Breaks down glycogen, detoxifies poisons, and stores calcium.

• Called smooth ER because it lacks ribosomes found on its surface

7. Golgi apparatus—processes and packages proteins and other substances produced in the ER

Golgi apparatus

• Flattened, round sacs that look like a sack of _pancakes_____. Receives, modifies, and ships products by way of _vesicles____ into the _cytosol → cell membrane_______

Found in animal cells only:

8. Lysosomes—cleans up the cell and digests unwanted materials

lysosomes

• Found in _animal__ cells only. Round sacs containing _enzymes___ that _break down___ and _recycle_____ used cell components. Also used as defense against _bacteria_____ and _viruses__

9. Vacuoles—sac-like structures may be used as storage for _water___, _molecules__, _or wastes.

• Plant cells usually contain a large vacuole that fills most of the cell—pressure from this large vacuole helps plants support themselves

10. Mitochondria—energy source of the cell (powerhouse – “Mighty mitochondria”)

Double-walled organelle with inner folds _to increase surface area____. Uses _glucose_____ to manufacture energy in the form of _ATP____. Mitochondria have their own _DNA____.

Found in plant cells only:11. Cell wall—provides support and

protection for cell• Composed mainly of cellulose (plant starch)—

fiber for our diet

12. Chloroplast—makes glucose using the energy from the sun (photosynthesis)

CHLOROPLAST

Found in _plant____ cells. Contain _chlorophyll_____ (green pigment) and their own _DNA______. Chloroplasts harvest energy from the _sun___ to produce _ATP___ through _photosynthesis___.

13. Centrioles

Found in _animal____ cells only. Bundles of _microtubules_______ that play a role in _cell division_____

14 Cytoskeleton—network of protein filaments that helps cell maintain its shape

CytoskeletonComposed of protein fibers known as _microtubules____ and _microfilaments_______. Anchor _organelles_____ and provide _structure_____. Also provide motility for some cells in the form of _cilia___ or _flagella____. More extensive cytoskeleton found in _animal___ cells.

Specialized Parts for movement:

1. Cilia (like little hairs) 2. Flagella (like a tail)

Specialized Cells:Different cells in your body do different jobs. The structure (how it’s built) of cells matches the function (what it does).

• Plant Examples:

1. Leaf cell—contains many chloroplasts to maximize photosynthesis

2. Root cell (potato)—contains many vacuoles to maximize water and starch storage

• Animal Examples:1. Epithelial cells—have villi to

increase nutrient absorption; found in the intestines

2. Muscle cells—contain many mitochondria to produce more energy for movement

3. Nerve cells—have fibers called dendrites that allow nerve cells to communicate

with each other

A deeper look into cells…

• Inside of Cell

• Cell Parts Description and Animation

Plant cells vs. Animal Cells

Plant cell Animal cell

Both