Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Wassily Kandinsky...

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Wassily Kandinsky (1866-1944)

Cells


Figure 4.1x

Cell Theory:

- all organisms are composed of cells

- all cells come from other cells


• Scanning electron microscope (SEM)

Figure 4.1B

TEM


• Cell size and shape relate to function

• Minimum

• Maximum

Figure 4.2


• A small cell has a greater ratio of surface area to volume than a large cell of the same shape

30 µm 10 µm

Surface areaof one large cube= 5,400 µm2

Total surface areaof 27 small cubes= 16,200 µm2Figure 4.3


• Prokaryotic cells - “before nucleus”

- small, relatively simple cells

–Single-celled organisms

–May not require oxygen

–No organelles (with membranes)

2 kinds of cells: prokaryotic and eukaryotic


• A prokaryotic cell has:

- plasma membrane

- rigid cell wall

– sticky capsule Ribosomes

Figure 4.4

Capsule

Cell wall

Plasmamembrane

Prokaryoticflagella

Nucleoid region(DNA)

Pili

– Nucleoid region with DNA

– Some w/ flagella


• Prokaryotic cells, Bacillus polymyxa

Figure 4.4x1


- true nucleus

- larger: 10-100 microns

- often multicellular

- organelles surrounded by membranes

- usually need O2

Eukaryotic cells - functional compartments


• a group of organelles that manufactures and distributes cell products

• nucleus

• endoplasmic reticulum (ER), ribosomes

• Golgi complex, vesicles

Endomembrane System


• largest organelle

• nuclear envelope

• contains DNA that directs cell’s activities

• DNA copy goes into every progeny cell

nucleus is the control center

ENDOMEMBRANE SYSTEM


Figure 4.6

Chromatin

Nucleolus

Pore

NUCLEUS

Two membranesof nuclearenvelope

ROUGHENDOPLASMICRETICULUM

Ribosomes

nuclear pores

nucleus


• Makes proteins, membranes

Rough endoplasmic reticulum

1 2

3

4Transport vesiclebuds off

Ribosome

Sugarchain

Glycoprotein

Secretory(glyco-) proteininside transportvesicle

ROUGH ER

Polypeptide Figure 4.8


SMOOTH ER

ROUGHER

Nuclearenvelope

Ribosomes

SMOOTH ER ROUGH ER

Figure 4.9


• The Golgi complex finishes, sorts, and ships cell products

Golgiapparatus

“Receiving” side ofGolgi apparatus

Transportvesiclefrom ER

Newvesicleforming

Transport vesiclefrom the Golgi

Golgi apparatus

“Shipping”side of Golgiapparatus Figure 4.10


• sacs of digestive enzymes budded off the Golgi

• Fuse with membrane around debris

Lysosomes

LYSOSOME

Nucleus

Figure 4.11A


• Lysosomal enzymes

– digest food

– destroy bacteria

– recycle damaged organelles

– function in embryonic development in animals

– Storage of undigestable waste Pombe’s disease - glycogen

Tay-Sachs disease - lipids


Figure 4.11B

Rough ER

Transport vesicle(containing inactivehydrolytic enzymes)

Golgiapparatus

Plasmamembrane

LYSOSOMES

“Food”

Engulfmentof particle

Foodvacuole

Digestion

Lysosomeengulfingdamagedorganelle


• synthesizes lipids

• regulates carbohydrate metabolism (liver)

• breaks down toxins and drugs (liver)

• Stores Ca++ in muscle cells

Smooth endoplasmic reticulum


• Nucleus, ribosomes, RER ,SER, Golgi, vesicles

Endomembrane system

Transport vesiclefrom ER

Rough ER

Transport vesiclefrom Golgi

Plasmamembrane

Vacuole

LysosomeGolgiapparatusNuclear

envelope

Smooth ER

Nucleus

Figure 4.14


• Vacuole in plants

– Lysosomal

– storage of pigments, poisons

– Water relations

Centralvacuole

Nucleus

Figure 4.13A


• plant cells

– large central vacuole

– rigid cell wall

– chloroplasts


• in plants and some protists

• convert solar energy to chemical energy in sugars

Chloroplasts

Chloroplast Stroma

Inner and outer membranes

Granum

IntermembranespaceFigure 4.15


Figure 4.16

Outermembrane

Mitochondrion

Intermembranespace

Innermembrane

Cristae

Matrix

• cellular respiration


• network of protein fibers

The CYTOSKELETON helps organize a cell’s structure and activities

Figure 4.17A


microfilamentIntermediate

filament

microtubule

Actin subunit Fibrous subunitsTubulinsubunit

7 nm 10 nm25 nm

Cell shape, movement

reinforce cell, anchor organelles

cell rigidity, anchor & tracks for organelles, mitosis


• Nuclei (yellow) and actin (red)

Figure 4.6x


• locomotor appendages

• composed of a core of microtubules wrapped in the plasma membrane

Cilia and flagella

Basal body


Surfaces allow exchange of signals and molecules.

• Plant cells connect by plasmodesmata

Cell surfaces protect, support, and join cells


Figure 4.19A

Vacuole

Layers of one plant cell wall

Walls of two adjacent plant cells

PLASMODESMATA

Cytoplasm

Plasma membrane


• Animal cells - surrounded by an extracellular matrix

–sticky layer of glycoproteins

–binds cells together in tissues

–can also protect and support cells


• Tight junctions can bind cells together into leakproof sheets

• Anchoring junctions link animal cells

• Gap junctions allow substances to flow from cell to cell

TIGHTJUNCTION

ANCHORING JUNCTION

COMMUNICATINGJUNCTION

Plasma membranes ofadjacent cells

ExtracellularmatrixFigure 4.19B


Eukaryotic organelles fall into 4 functional groups

• 1. Manufacture and transport – dependent on network of membranes

- Nucleus

- Ribosomes

- Rough, smooth ER

- Golgi apparatus


2. Breakdown – all single-membrane sacs

• Lysosomes (in animals, some protists)

• Peroxisomes

• Vacuoles (plants)


3. Energy Processing – involves extensive membranes embedded with enzymes

• Chloroplasts

• Mitochondria


4. Support, Movement, Communication

• Cytoskeleton – includes cilia, flagella, filaments, microtubules

• Cell walls

• Extracellular matrix

• Cell junctions

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Wassily Kandinsky...

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