Unit 3Unit 3

Section Sec 7.2Cell Structure

Animal and Plant Cells Have More Similarities Than Differences

1. Cell Membrane1. Cell Membrane

Cell Membrane:Controls what enters and leaves cell

through selective permeability Boundary of every cell

a. Membrane Lipidsa. Membrane Lipids

Phospholipid bilayer:Polar hydrophilic headNonpolar hydrophobic tail

Cell MembraneCell Membrane

c. Fluid Mosaic Model

Phospholipid bilayer acts more like a fluid than a solid

2. 2. Cell Wall

Only located in plant cells Surrounds ____________ Functions:

A Consequence of Cell Walls – the Great Strength of Woody Plants

3. Nucleus3. Nucleus

Functions: Store

Nuclear Membrane: double membrane barrier enclosing nucleus

Chromatin: carries ______, coils together to form chromosomes

The Nucleus Think of the nucleus as the cell’s control center.

Two meters of human DNA fits into a nucleus that’s 0.000005 meters across.

4. Cytoplasm4. Cytoplasm

Cytoplasm: entire region between nucleus and cell membrane

Contains cytosol:

Cellular Anatomy

We’ll start by seeing what role these parts play in making and moving proteins.

1. Mitochondria

1. Mitochondria: ________________

Site of Cellular Respiration:

Cristae: inner membrane to increase surface area for reactions

The Mitochondrion

Think of the mitochondrion as the powerhouse of the cell.

Both plant and animal cells contain many mitochondria.

(Mitochondria is the plural of mitochondrion)

The Mitochondrion

A class of diseases that causes muscle weakness and neurological disorders are due to malfunctioning mitochondria.

Worn out mitochondria may be an important factor in aging.

2. Ribosomes2. Ribosomes

Ribosomes:Site of ______

SynthesisMade of

ribosomal RNA and proteins

Ribosomes and the Endoplasmic Reticulum

3. Endoplasmic Reticulum (ER)3. Endoplasmic Reticulum (ER)

-Like a highway, transporting material from one part to anotherRough ER:

Produces components of CMSmooth ER:

make lipids, metabolize carbs., breakdown drugs and poisons

4. Golgi Apparatus4. Golgi Apparatus

Golgi Apparatus: Products of the ER are sent over, modified,

stored, and sent out in vesicles

The Golgi Apparatus (or Complex)

Think of the Golgi apparatus as a busy airport receiving passengers (proteins) and sending them to their destinations.

5. Lysosomes5. Lysosomes

Lysosomes:Using enzymes and Hydrolysis, they digest

macromolecules like proteins and carbohydratesVideo

The Lysosome

Cell suicide (suicide is bad for cells, but good for us!)

Recycling cellular components

Functions:

Digesting food or cellular invaders

(The lysosome is not found in plant cells)

The Lysosome

This bacterium about to be eaten by an immune system cell will spend the last minutes of its existence within a lysosome.

6. Vacuoles6. Vacuoles

Vacuoles: storage and waste control

Two Other Unique Features of Plant Cells

The central vacuole may occupy 90% of a plant cell.

7. Cytoskeleton7. Cytoskeleton

7. Cytoskeleton:Gives __________ and maintains shape of

cellCan adjust for movement

Cytoskeleton

A Cytoskeleton Gallery

The name is misleading. The cytoskeleton is the skeleton of the cell, but it’s also like the muscular system, able to change the shape of cells in a flash.

The Cytoskeleton

An animal cell cytoskeleton

8. Cilia and Flagella8. Cilia and Flagella

Cilia and Flagella: extend from cells used to propel organism Cilia: a large number of short hair-like

extensions Flagella: smaller in number and longer in length

Cilia on a protozoan. Beating sperm tail at fertilization.

9. Chloroplast9. Chloroplast

Site for photosynthesis

The Chloroplast

Think of the chloroplast as the solar panel of the plant cell.

Only plants have chloroplasts, but animals reap the benefits too.

Cells In a Leaf

Centrioles: Assist the cell in movement of chromosomes during cell reproduction

10. Centrioles

Ticket out the Door: Write the Ticket out the Door: Write the questions and answersquestions and answers

1. Identify and describe 2 parts of the cell that present in a plant cell but not an animal cell?

2. What do ribosomes do?

3. What is the nucleus surrounded by?