Eukaryotic Cell Structure & Function

Plant Cell

Plant Cell

Nuclearenvelope

Ribosome(attached)

Ribosome(free)

Smooth endoplasmicreticulum

Nucleus

Rough endoplasmic reticulum

Nucleolus

Golgi apparatus

Mitochondrion

Cell wall

CellMembrane

Chloroplast

Vacuole

Section 7-2

Figure 7-5 Plant and Animal Cells

Animal Cell

Animal Cell

Centrioles

NucleolusNucleus

Nuclearenvelope

Rough endoplasmic reticulum

Golgi apparatus

Smooth endoplasmicreticulum

Mitochondrion

CellMembrane

Ribosome(free)

Ribosome(attached)

Section 7-2

Figure 7-5 Plant and Animal Cells

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cd

e

f

g

hi

j

k

Function

The Cell Theory

• All living things are composed of cells

• Cells are the basic units of structure & function in living things

• New cells are produced from existing cells

Organelles & Cell Division

• Cells are made of specialized structures known as organelles

• Cell biologists divide cells into 2 parts – Nucleus– cytoplasm

Cell Membrane (plant & animal)

• Separates inside of cell from the outside• Phospholipid bilayer and proteins

Cytoplasm (plant & animal)

• Fluid part of the cell that is outside the nucleus

• Houses the organelles

Nucleus (plant & animal)

• Control center• Surrounded by nuclear envelope

– 2 membranes with pores• Allows for movement of information into & out of the

nucleus

• Visible material = chromatin– DNA bound to protein

• Nucleolus – small dense region where ribosome assembly begins

Ribosomes (plant and animal)

• Small particles of RNA & proteins found through out the cytoplasm

• Proteins are made on the ribosomes– Follow coded instructions from the nucleus

Endoplasmic Reticulum (both)

• Internal membrane system• lipid components of cell membrane are

assembled • proteins & other materials are exported from

the cells

Rough & Smooth ER (both)

• Rough ER – involved in protein synthesis– b/c has ribosomes on surfaces

• Smooth ER – has collections of enzymes performing specialized tasks– b/c NO ribosomes

Golgi Apparatus (both)

• Looks like a stack of closely apposed membranes

• Modify, sort & package proteins & other materials from ER

• Proteins are shipped from here to their final destination

Lysosomes (plant and animal)

• Small organelles filled with enzymes• Gets rid or the “junk”

– Digestion of:• Lipids• Carbohydrates• Proteins• Breaks into small molecules to be used by cell

– Break down old organelle

Vacuoles (plant & animal)

• A saclike structure• A storage place for:

– Water– Salts– Proteins– Carbohydrates

• In plant cells: single, large, provides support b/c of pressure

Mitochondria (plant & animal)

• The power house• Convert chemical energy in food into

compounds that are more convenient for cells• Enclosed by 2 membranes• Contains it own DNA molecules• Come from MOM

Chloroplasts (plant only)

• Capture energy from sunlight• Convert it to chemical energy through

photosynthesis• Surrounded by 2 membranes• Contains chlorophyll• Contains small DNA molecules

Cell Wall (plant only)

• Made of cellulose • Provides support and

structure• Surrounds the cell

membrane

Cytoskeleton (plant & animal)

• A system of protein filaments structures– Provide supports & organization– Involved in movement

• Microfilaments• Microtubules

Microfilaments

• Thread like structures made of actin– Protein

• Tough but flexible • Movement caused by assembly & disassembly

of these structures– Allows for crawling such as amoebas

Microtubules

• Hollow structures made of tubulins– Proteins

• Maintain shape• Important for cell division

– Form centrioles -- help to organize cell division

• Form projections – cilia & flagellum – Rapid swimming through liquids

Function

What structures are found in plant cells but not animal cells? Why are

these structures important for plants?

What are prokaryotic cells?