A Tour of the Cell

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4

The logistics of carrying out cellular metabolism sets limits on the size of cells

The surface area to volume ratio of a cell is critical

As the surface area increases by a factor of n2, the volume increases by a factor of n3

Small cells have a greater surface area relative to volume

Slide 27

Fig. 6-8

Surface area increases while

total volume remains constant

5

1

1

6

150

750

125

125

1

6

6

1.2

Total surface area

[Sum of the surface areas

(height  width) of all boxes

sides  number of boxes]

Total volume

[height  width  length 

number of boxes]

Surface-to-volume

(S-to-V) ratio

[surface area ÷ volume]

Slide 28

A Panoramic View of the Eukaryotic Cell

A eukaryotic cell has internal membranes that partition the cell into organelles

Plant and animal cells have most of the same organelles

BioFlix: Tour Of An Animal Cell

BioFlix: Tour Of A Plant Cell

Slide 29

Fig. 6-9a

ENDOPLASMIC RETICULUM (ER)

Smooth ER

Rough ER

Flagellum

Centrosome

CYTOSKELETON:

Microfilaments

Intermediate

filaments

Microtubules

Microvilli

Peroxisome

Mitochondrion

Lysosome

Golgi

apparatus

Ribosomes

Plasma membrane

Nuclear

envelope

Nucleolus

Chromatin

NUCLEUS

Slide 30

Fig. 6-9b

NUCLEUS

Nuclear envelope

Nucleolus

Chromatin

Rough endoplasmic reticulum

Smooth endoplasmic reticulum

Ribosomes

Central vacuole

Microfilaments

Intermediate filaments

Microtubules

CYTO-

SKELETON

Chloroplast

Plasmodesmata

Wall of adjacent cell

Cell wall

Plasma membrane

Peroxisome

Mitochondrion

Golgi

apparatus

Slide 31

Concept 6.3: The eukaryotic cell’s genetic instructions are housed in the nucleus and carried out by the ribosomes

The nucleus contains most of the DNA in a eukaryotic cell

Ribosomes use the information from the DNA to make proteins

Slide 32

The Nucleus: Information Central

The nucleus contains most of the cell’s genes and is usually the most conspicuous organelle

The nuclear envelope encloses the nucleus, separating it from the cytoplasm

The nuclear membrane is a double membrane; each membrane consists of a lipid bilayer

Slide 33