VHS Honors Biology Unit #2 (Cells)

What is the function of the cytoplasm?

a. the jelly-like substance and organelles/internal cell structures floating in it

b. everything inside a cell between the nucleus and the plasma membrane

Define prokaryotic.

A cell that does NOT have a nucleus or membrane-bound organelles.

Define eukaryotic.

A cell that has a nucleus and membrane bound organelles.

What is the plasma membrane composed of?

phospholipids and proteins

What is the function of the plasma membrane?

It allows certain molecules to enter/leave the cell.

What is the function of the nucleus?

stores and protects the nucleic acids; control center of the cell

Describe the nuclear envelope.

a. two phospholipid bilayers that surround the nucleus

b. contains nuclear pores

What is the function of nuclear pores?

control what enters/leaves the nucleus

What is the function of the nucleolus?

produces rRNA and proteins = ribosomes

What is the function of mitochondria?

a. transfer energy from organic molecules to ATP

b. perform cellular respiration

What is the function of a ribosome?

protein synthesis (translation)

Where are ribosomes located within a eukaryotic cell?

a. floating free in the cytoplasm

b. attached to the RER

What is the main function of the endoplasmic reticulum (ER)?

main function is movement of materials

What are the functions of RER?

*produces membranes (phospholipids are made by enzymes in the RER)

*produces proteins destined for secretion

What are the functions of SER?

*produces lipids

*stores/releases calcium ions in muscle cells

*enzymes in the SER of liver cells help process drugs and other potentially harmful substances

What is the function of the Golgi?

modifies, stores, and ships products of the ER

Where does the Golgi receive vesicles from?

the ER

What is the function of a lysosome?

removing or recycling damaged parts of a cell, digesting organic macromolecules, digesting food particles in protists, and destroying bacteria in humans

Describe the contents of a lysosome.

hydrolytic enzymes in an acidic environment

What are the functions of a peroxisome?

a. membranous sacs containing enzymes that neutralize free radicals

b. detoxify alcohol

c. produce H2O2 when breaking down alcohol and killing bacteria

d. break down fatty acids

Name the three parts of the cytoskeleton.

a. microtubules

b. microfilaments

c. intermediate filaments

Describe cilia.

a. numerous, short, hair-like structures on the outside of a cell or organism

b. made of microtubules (arranged in a 9+2 pattern) wrapped in an extension of the plasma membrane

c. used for locomotion (usually unicellular cells) or to move materials outside the cell or organism

d. only found in eukaryotes, but not in plant cells

Describe flagella.

a. few, long, whip-like structures on the outside of a cell or organism

b. made of microtubules (arranged in a 9+2 pattern) wrapped in an extension of the plasma membrane

c. used for locomotion (usually unicellular cells)

d. found in both prokaryotes and eukaryotes, in both animal and plant cells

Describe centrioles.

a. composed of microtubules

b. organize microtubules (spindle fibers) during cell division

c. found in animal, but not plant cells

What are the functions of a cell wall?

support and protection

What is a plant cell wall composed of?

cellulose

Which organisms have a cell wall?

a. all plants

b. all fungi

c. some protists (algae)

d. some prokaryotes

NOTE: The cell wall of these organisms are composed of different materials (NOT cellulose).

What is the function of the central vacuole?

stores water and pushes the plasma membrane against the cell wall, making the plant stiff (turgid)

What else can vacuoles store?

toxic materials, wastes, or pigments

What is the function of a chloroplast?

perform photosynthesis (the conversion of light energy to chemical energy of sugar molecules)

Name the unique characteristics of chloroplasts.

a. Chloroplasts contain their own DNA, ribosomes, and enzymes.

b. Chloroplasts replicate much like prokaryotes.

What is the function of a chromoplast?

They contain colorful pigments that may or may not be involved in photosynthesis

Name the three parts of the Cell Theory

1. All organisms are composed of one or more cells.

2. Cells are the basic units of structure and function in an organism.

3. Cells come only from the reproduction of existing cells.

A large surface area-to-volume ratio allows small cells to quickly and effectively:

a. Exchange materials (obtain nutrients and oxygen; dispose of wastes) with the environment.

b. Distribute (diffuse) materials inside the cell.

Name the three basic parts of a cell.

a. plasma membrane

b. cytoplasm

c. DNA

Name two groups of prokaryotes.

bacteria and Archaea

How do prokaryotes differ from eukaryotes?

a. Prokaryotes have smaller ribosomes than eukaryotic ribosomes (susceptible to antibiotics).

b. Prokaryotes do not have a nucleus or membrane bond organelles.

Describe cellular organization.

Cells -> Tissue -> Organ -> Organ System -> Organism