Click here to see The Inner life of the cell

I. Cell Structure + FunctionCh. 3 pg. 47

A. Cell Theory

1. All living things are made of cells2. All cells come from pre-existing cells

This leukemia cell is tearing itself apart by a process called apoptosis.

E. coli bacteria inthe large intestine Red blood

cells

What Are the Basic Features of Cells?

The Plasma Membrane Encloses the Cell and Mediates Interactions Between the Cell and Its Environment

All Cells Use DNA as a Hereditary Blueprint and Contain Cytoplasm

All Cells Obtain Energy and Nutrients from Their Environment

Cell Function Limits Cell Size

frog embryo

most eukaryotic cells

mitochondrion

most bacteria

virus

proteins

diameter of DNA double helix

chicken egg

adult human

tallest trees

atoms

1 centimeter (cm) = 1/100 m1 millimeter (mm) = 1/1000 m

Units of measurement: 1 meter (m) = 39.37 inches

Diameter

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1 micrometer (µm) = 1/1,000,000 m1 nanometer (nm) = 1/1,000,000,000 m

100 µm

10 µm

1 µm

100 nm

10 nm

1 nm

0.1 nm

1 mm

1 cm

10 cm

100 m

10 m

1 m

most eukaryotic cells

mitochondrion

most bacteria

virus

proteins

diameter of DNA double helix

atoms

1 centimeter (cm) = 1/100 m1 millimeter (mm) = 1/1000 m

Units of measurement: 1 meter (m) = 39.37 inches

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1 micrometer (µm) = 1/1,000,000 m1 nanometer (nm) = 1/1,000,000,000 m

100 µm

10 µm

1 µm

100 nm

10 nm

1 nm

0.1 nm

What Are the Basic Features of Cells?

There Are Two Basic Types of Cells: Prokaryotic and Eukaryotic

Prokaryotic cells – represented by the Domains Archaea (archaebacteria) and Bacteria

Eukaryotic cells – represented by the Domain Eukarya (algae, protozoans, fungi, plants and animals)

chromosome(nucleoid region)

piliribosomes

food granule

prokaryoticflagellum

capsule orslime layer

cell wall

plasma membranecytoplasmplasmid (DNA)

A generalized prokaryotic cell

mitochondrionvesicle

cytoplasm

flagellum

lysosome

centriole

Golgi complex

vesicle

nuclear pore

nuclear envelope

chromatin (DNA)nucleolus

nucleus

ribosome

free ribosome

microtubules

rough endoplasmicreticulum

Smooth endoplasmicreticulum

plasmamembrane

intermediatefilaments

A generalized animal cell

central vacuole

plastid mitochondrion

vesicle plasmodesma

cell wall

plasmamembrane

intermediatefilaments

free ribosomeribosomes

nucleusnucleolus

nuclear porechromatin

nuclear envelope

Golgi complex

chloroplast

Microtubules (part of cytoskeleton)

smoothendoplasmicreticulum

roughendoplasmicreticulum

generalized plant cell

What Are the Major Features of Prokaryotic Cells?

Prokaryotic Cells Are Small Prokaryotic Cells Have Fewer

Specialized Structures Within Their Cytoplasm

Have no membrane-enclosed organelles within their cytoplasm

DNA is located in the “nucleoid”

What Are the Major Features of Eukaryotic Cells?

Eukaryotic Cells Contain Organelles The Nucleus Is the Control Center of

the Eukaryotic Cell (Have the DNA) Have membrane-enclosed organelles

within the cytoplasm

Functions of Cell Structures Eukaryotic Cells Contain a Complex System of

Membranes The Plasma Membrane Both Isolates the Cell

and Allows Selective Interactions Between the Cell and Its Environment

The Endoplasmic Reticulum Forms Membrane-Enclosed Channels Within the Cytoplasm

The Golgi Complex Sorts, Chemically Alters, and Packages Important Molecules

smoothendoplasmicreticulum

nuclear envelope

Golgi complex

exocytosisplasma membrane

phagocytosis

lysosomefused withfood vacuole

food vacuole

roughendoplasmicreticulum

The flow of membrane within the cell

B. Cell Organelles1. Cell membrane

i) Based on “fluid mosaic model” (moves around constantly)

a) Phosopholipid bilayer with protein scattered throughout ii) Selectively permeable

iii) Glycolipid and Glycoproteins on surface of membrane identifies the cell to the immune system

2. Mitochondria i) “powerhouse” of the cell

ii) 2 membranes

iii) Site of cellular respiration

Glucose + O2 ATP + CO2

MatrixCristae

(inner membrane)

Outer membrane

3. Endoplasmic Reticulum (ER)i) tubular canals for intracellular transport

ii) Smooth E.R – no ribosomes, lipid synthesis

iii) Rough E.R – contains ribosomes for protein synthesis

Composed of 2 protein subunits and R-RNA functions in protein systhesis

4. Ribosomes

• Packaging and storage of secretory products• Eg. Hormones, neurotransmitters

5. Golgi Apparatus

6. Lysosomes water to split

• Contains hydro/lytic enzymes for intracellular digestion (found on head of sperm)

7. Nucleusi) Controls cell by controlling protein synthesis

ii) Composed of a nuclear envelope surrounding chromosomes (DNA) and nucleoli

iii) Nucleolus- contains chromatin (condensed chromosomes) required to make R-RNA

Differences between plant and animal cells

Plant cells are surrounded by a rigid cell wall Plant cells have chloroplast Plant cells have a large central vacuole Plant cells contain plasmodesmata-openings in

the cell wall of adjacent cells Animal cells have lysosomes Animal cells have Centrioles