3.2 Cell Organelles - Holy Family Catholic Schoolsteachers.holyfamilydbq.org/.../08/2011-3-2-Cell-Organelles-PPT.pdforganelles with their own DNA ... 3.2 Cell Organelles ... give the

3.2 Cell Organelles

KEY CONCEPT Eukaryotic cells share many similarities.

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ENDOSYMBIOTIC THEORY

• In 1970, American biologist, Lynn Margulis, provided evidence that some organelles within cells were at one time free living cells themselves

• Supporting evidence included organelles with their own DNA

• Chloroplast and Mitochondria

3.2 Cell Organelles

Cells have an internal structure.

• The cytoskeleton has many functions.

–supports and shapes cell

–helps position and transport organelles

–provides strength

–assists in cell division

–aids in cell movement

3.2 Cell Organelles

Several organelles are involved in making

and processing proteins.

• The nucleus stores genetic

information.

3.2 Cell Organelles

Several organelles are involved in making

and processing proteins.

• The nucleus stores genetic information.

• Many processes occur in the endoplasmic

reticulum.

3.2 Cell Organelles

Several organelles are involved in making

and processing proteins.

• The nucleus stores genetic information.

• Many processes occur in the endoplasmic

reticulum.

• There are two types of endoplasmic reticulum.

–rough endoplasmic

reticulum

–smooth endoplasmic

reticulum

3.2 Cell Organelles

Several organelles are involved in making and

processing proteins. (continued)

• Ribosomes link amino acids to form proteins.

• Vesicles are membrane-bound sacs that hold

materials.

3.2 Cell Organelles

Other organelles have various functions.

• Mitochondria supply energy to the cell.

• Vacuoles are fluid-filled sacs that hold materials.

3.2 Cell Organelles

Other organelles have various functions.

• Lysosomes contain enzymes to digest material.

• Centrioles are tubes found in the centrosomes.

–Centrioles help divide DNA.

–Centrioles form cilia and flagella.

3.2 Cell Organelles

Plant cells have cell walls and chloroplasts.

• A cell wall provides rigid support.

• Chloroplasts convert solar energy to chemical

energy.

Similarities between plant cells and animal cells

Both have a cell membrane surrounding the cytoplasm

Both have a nucleus

Both contain mitochondria

Differences between plant cells and animal cells

Animal cells Plant cells

Relatively smaller in size

Irregular shape

No cell wall

Relatively larger in size

Regular shape

Cell wall present

Animal cells Plant cells

Vacuole small or absent

Glycogen as food storage

Nucleus at the center

Large central vacuole

Starch as food storage

Nucleus near cell wall

Differences between Plant Cells and Animal Cells

3.2 Cell Organelles

Misconception

• Because of they way most cells are drawn in pictures, with

only one or two of each type of organelle, students think

that a cell is a loose bag of cytoplasm large amounts of

open space

FACT

• Organelles are actually so numerous they bump into other

organelles and the cytoskeleton constantly and help to

give the cell its shape.

Word Roots Knowing word roots can improve your

vocabulary! -ell = small (organelle: a small formed body with a specialized function found in the cytoplasm of eukaryotic cells)

endo- = inner (endomembrane system: the system of membranes within a cell that includes the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, and the plasma membrane)

eu- = true (eukaryotic cell: a cell that has a true nucleus)

extra- = outside (extracellular matrix: the substance in which animal tissue cells are embedded)