Plant & Animal Cells

The Cell Story

• Robert Hooke- in 1665 he discovered the cell composition of cork and introduced the word “cell” to science

• Anton von Leeuwenhoek was first to observe one celled living things. Examples of these were bacteria and parameciums

• Robert Brown- in 1830, he identified a dark-stained structure at the center of every cell he observed. He referred to such structure as the nucleus.

The Cell Theory• All living things are

made up of cells• Cells are the basic unit

of structure and function in living things

• Living cells come only from other living cells

• Rudolph Virchow

Matthias Schleiden

Theodor Schwann

• 1838- a German botanist discovered that all plants were composed of cells

• 1839- a German zoologist discovered that all animals were composed of cells

• 1856- a German physician was doing an experiment when he found that all cells come from other existing cells

Schwann

Matthias Schleiden Theodor Schwann Rudolph Virchow

Two Fundamentally Different Types of Cells

A prokaryotic cell

A eukaryotic cell

Eukaryotes and Prokaryotes

Animal and Plant Cells Have More Similarities Than Differences

Organelles maintain the life processes of the cell, including:

Intake of nutrientsMovementGrowthResponse to stimuliExchange of gasesWaste removalReproduction

The Purpose of Organelles

•Cytoplasm refers to the jelly-like material with organelles in it.

If the organelles were removed, the soluble part that would be left is called the cytosol. It consists mainly of water with dissolved substances such as amino acids in it.

Cell Wall• Is a stiff non-living wall

that surrounds the cell membrane made of

cellulose• Protects the cell from

injury• Gives the plant cell a

fixed shape• Cell wall is fully

permeable

• Cytoskeleton Is a network of thin

fibrous filaments that serve as the “bones and muscles” of cells. Microfilaments are cytoskeletons that are also attached to the cell membrane. They are responsible for giving the cell its shape. Microtubules are cytoskeletons that are not connected to the cell membrane. They serve as the anchorage of the organelles in the cell

• Nucleusit is a membrane bound organelle, spherical in shape enclosed by a nuclear envelop.

Most of the activities of the cell is directed by the nucleus.

• Nucleolusdark spot in the middle of the nucleus that helps make ribosomes

Nucleus

Nucleolus

Nuclear Envelope

• Ribosomesare found on the endoplasmic reticulum.

Together they help in manufacturing proteins for the cell following instructions of the nucleus

Ribosomes

• Endoplasmic Reticulumis a membranous structure forming a network of canals through which proteins and other molecules are transported

Smooth Endoplasmic ReticulumRough Endoplasmic

Reticulum

• Rough Endoplasmic Reticulumis an organelle where most of the ribosomes are attached. Proteins produced in the ribosomes needs to be transported through the Rough endoplasmic reticulum

Smooth Endoplasmic ReticulumRough Endoplasmic

Reticulum

• Smooth Endoplasmic Reticulumis a branching canal (without ribosomes) that transports large molecules inside the cell.

Smooth Endoplasmic ReticulumRough Endoplasmic

Reticulum

• Golgi Complexthey are flattened stacks of membrane bound sacs. They function as the packaging unit, the protein formed by the endoplasmic reticulum are packed into small membrane sacs called vesicles. Golgi Complex

• Lysosomesorganelles that contain hydrolytic enzymes (lysozymes) that digest bacteria, viruses, complex food particles, and damaged cell components that could be harmful to the cell, and may interfere with its normal activities.

Cell suicide (suicide is bad for cells, but good for us!)(The lysosome is not found in plant cells)

• Mitochondria are small, double-membraned, spherical or sausage-shaped organelles involved in the production of energy. The mitochondria is popularly known as the powerhouse of the cell.

Mitochondria

Plant Cell

• Vacuole a small cavity in the cytoplasm of a cell, bound by a single membrane and containing water, food, or metabolic waste

Vacuole

• Plastidsare double-membraned organelles found in plant cells, some protozoans, and bacteria. Chloroplastids or chloroplasts are the most common plastids in green plants. It contains green pigments called chlorophyll. Chloroplast are the energy-capturing centers in plant cells, which are involved in the manufacture of the cell’s food, a process known as photosynthesis.

• Chloroplastschlorophyll containing organelles found in cells of green plants and some protist; capture light energy and converted it to chemical energy

Chloroplasts

Chloroplasts

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

• Cell wallis an additional boundary surrounding the cells of plants, fungi, bacteria, and some protozoans. The cell wall of plant cells is a very tough substance made up of cellulose, which support the cells and protects it from injury. The wood of fully-grown plants is basically made up of cell wall.

Cell Wall

• Vesiclesare organelles that carry materials in and out of the cell. These materials include food particles needed by the cell and waste products secreted by the cell.

Plant Cell

Cell Membrane

Vacuole

Chloroplasts

Cell Wall

NucleolusNucleus

Rough ER

Smooth ER

Golgi Bodies

Mitochondria

RibosomesCytoplasm