Topic 7: Cell Structures

Question 1

What structures do prokaryotes and eukaryotes have in common? What are their major differences?

Answer 1

Common:
1) Plasma Membrane
2) Cytoplasm
3) DNA
4) Ribosomes

Differences:
Eukaryotic cells contain a nucleus, organelles, and chromosomes. Eukaryotic can be multicellular and unicellular.
Prokaryotic cells are only unicellular

Question 2

Describe organelles of eukaryotic cells and describe their function.

Answer 2

1) Plasma Membrane: Controls what comes in and out of the cell.

2) Nucleus: Houses the cells DNA and direct synthesis of ribosome and proteins

3) Ribosomes: Responsible for protein synthesis. Proteins are essential in every cell which ribosomes are in every cell.

4) Mitochondria: Responsible for the making of ATP (Adenosine Triphosphate). Fun fact: They have their own ribosomes and DNA and plasma membrane.

5) Peroxisome: Carry out oxidation reactions that break down fatty acids and amino acids. They have role in metabolism, can detoxify poisons, pathogen defense, and stress response.

6) Vesicle and Vacuoles: Membrane bound sacs that function in storage and transport.
Vesicle: Transport - materials within the cytoplasm
Vacuoles: Storage - Hold various molecules and substances together.

7) The Centrosome: pairs of centrioles that replicate before a cell divides.

8) Lysosomes: Is very acidic. Its enzymes break down macromolecules and worn out organelles. Acts as a garbage disposal.

9) The Cell Wall: Gives cell shape, support, and protection.

10) Chloroplasts: They carry out photosynthesis

11) The Central Vacuole: Regulates the cells water concentration in changing environmental conditions.

Question 3

Give examples of cells that are specialized for specific functions in the human body. Which organelles would you expect to be predominant in the cell?

Answer 3

White Blood Cells: Mitochondria and Peroxisome - energy and defense

Muscle Cells: Mitochondria - energy

Skeletal Cells: Endoplasmic Reticulum - signaling

Question 4

Explain theory of endosymbiosis.

Answer 4

Endosymbiosis is the theory that an eukaryotic cell ancestor engulfed an aerobic bacteria which became a mitochondria. Then in the plant area the cell engulfed a photosynthetic bacteria to make chloroplasts.

Question 5

What are the main differences between animal and plant cells?

Answer 5

Animal Cells have lysosomes and Centrosomes

Plant cells have a cell wall , chloroplasts, plastids, and a large central vacuole