Organelles, Cell Types, and Cell Structure

What is the main function of the plasma membrane?

Separates the cell from its environment and regulates what enters and leaves the cell.

Which structure is responsible for regulating what enters and leaves the cell?

Plasma membrane

What is the basic structure of the plasma membrane?

A phospholipid bilayer with embedded proteins.

Which structure consists of two layers of phospholipids?

Phospholipid bilayer

What is the cytosol?

The watery fluid inside the cell.

What is the cytoplasm?

The space inside the plasma membrane that contains the cytosol and cellular structures.

What is the main function of the nucleus?

It houses the cell's DNA.

Which organelle contains the cell's genetic material?

Nucleus

What structure surrounds the nucleus and contains pores that allow materials to enter and leave?

Nuclear envelope

What is chromatin?

DNA and associated proteins found inside the nucleus.

Which structure is a region of condensed chromatin where ribosomes are synthesized?

Nucleolus

What is the main function of the nucleolus?

Synthesizing ribosomes.

What is the main function of ribosomes?

Protein synthesis.

Which cellular structure uses instructions from DNA to build proteins?

Ribosomes

True or False: Ribosomes are found only in eukaryotic cells.

False. Ribosomes are found in both prokaryotic and eukaryotic cells.

Where can ribosomes be found in a eukaryotic cell?

Some are attached to the rough ER and some are free in the cytoplasm.

What gives the rough endoplasmic reticulum its rough appearance?

Ribosomes attached to its surface.

What is the main function of the rough ER?

It synthesizes membrane and secretory proteins.

Which organelle synthesizes membrane and secretory proteins and has ribosomes attached to it?

Rough endoplasmic reticulum (rough ER)

What is the main function of the smooth ER?

Lipid synthesis.

Which organelle is the site of lipid synthesis and does not have ribosomes attached to its surface?

Smooth endoplasmic reticulum (smooth ER)

What is the main structural difference between rough ER and smooth ER?

Rough ER has ribosomes attached to it; smooth ER does not.

A cell needs to synthesize lipids. Which organelle would be especially important?

Smooth ER

A cell needs to produce membrane and secretory proteins. Which organelle would be especially important?

Rough ER

What is the main function of the Golgi apparatus?

It modifies, sorts, and routes proteins and lipids to their destinations.

Which organelle modifies, sorts, and routes proteins and lipids?

Golgi apparatus

What is the basic structure of the Golgi apparatus?

Stacks or layers of flattened membranes.

A protein has been synthesized by the ER and needs to be modified and sorted. Which organelle handles it?

Golgi apparatus

What is the main function of mitochondria?

Producing ATP for the cell.

Which organelle has an outer membrane and a highly folded inner membrane?

Mitochondrion

A cell requires large amounts of ATP. Which organelle would be especially important?

Mitochondria

What is the main function of lysosomes?

Digesting materials.

Which organelle is associated with digesting materials in the cell?

Lysosome

What is the main function of peroxisomes according to the course material?

They metabolize waste.

Which organelle is associated with the metabolism of waste?

Peroxisome

What is the main function of vacuoles?

Storage.

Which organelle is a membrane-bound structure that can store materials?

Vacuole

Which organelle is especially large in plant cells and helps maintain pressure against the cell wall?

Central vacuole

What is the function of the central vacuole in plant cells?

It maintains pressure against the cell wall.

What is the main function of chloroplasts?

Photosynthesis.

Which organelle is responsible for photosynthesis?

Chloroplast

What is the basic structure of a chloroplast?

It has an outer membrane, an inner membrane, and stacks of membranes inside the inner membrane.

A plant cell needs to perform photosynthesis. Which organelle is required?

Chloroplast

What is the function of plastids?

They store pigments.

Which plant-cell structure stores pigments?

Plastid

What is the main function of the cell wall in plant cells?

It provides structural support and is located outside the plasma membrane.

Where is the plant cell wall located relative to the plasma membrane?

Outside the plasma membrane.

Which structures are found in plant cells but not animal cells?

Cell wall, chloroplasts, and central vacuole.

Which structures are identified in the course as animal-cell structures not found in plant cells?

Lysosomes and centrosomes.

What is the main function of the cytoskeleton?

Structural support, organization, anchoring, and movement.

Which cellular structure is a network of fibers that provides structural support, organization, anchoring, and movement?

Cytoskeleton

What are the three types of cytoskeletal components emphasized in Chapter 6?

Microtubules, intermediate filaments, and microfilaments.

Which cytoskeletal component lines the cell membrane and makes up the cellular cortex?

Microfilaments

Which cytoskeletal component helps hold organelles in place?

Intermediate filaments

Which cytoskeletal component forms the mitotic spindle and helps maintain cell shape?

Microtubules

Which cytoskeletal component is associated with holding organelles in place?

Intermediate filaments

Which cytoskeletal component forms the mitotic spindle?

Microtubules

Which cytoskeletal component makes up the cellular cortex?

Microfilaments

What is the main function of the centrosome?

It functions as a microtubule-organizing center.

What is the structure of a centrosome?

Two tubular structures positioned at right angles to one another.

Which structure functions as the microtubule-organizing center?

Centrosome

True or False: Plant cells have centrosomes.

False.

What structure allows plant cells to exchange materials directly with neighboring plant cells?

Plasmodesmata

What are plasmodesmata?

Channels that pass through the plasma membranes and cell walls of adjacent plant cells.

What are plasmodesmata used for?

Communication and exchange of materials between neighboring plant cells.

Which structure is essentially the plant-cell equivalent of an animal cell gap junction?

Plasmodesmata

What is the function of gap junctions in animal cells?

They allow neighboring cells to exchange materials and signals.

What is the function of desmosomes?

They strongly anchor neighboring animal cells together.

What is the function of tight junctions?

They create a seal between cells that prevents substances from leaking between them.

What is the defining feature of a eukaryotic cell?

It has a membrane-bound nucleus.

What is the defining feature of a prokaryotic cell?

It lacks a nucleus and membrane-bound organelles.

Which type of cell is always single-celled according to the course material?

Prokaryotic

Which organisms contain prokaryotic cells?

Bacteria and Archaea

Which organisms contain eukaryotic cells?

Protists, fungi, plants, and animals.

Which type of cell is generally larger and more structurally complex?

Eukaryotic

True or False: Both prokaryotic and eukaryotic cells contain DNA, ribosomes, a plasma membrane, and cytosol.

True

Which type of cell contains membrane-bound organelles?

Eukaryotic cells

Which type of cell does not contain membrane-bound organelles?

Prokaryotic cells

Where is DNA located in a prokaryotic cell?

In the nucleoid region.

What is the nucleoid?

The region of a prokaryotic cell where its DNA is found.

Does a prokaryotic cell have a nucleus?

No.

Does a eukaryotic cell have a nucleus?

Yes.

A cell contains ribosomes but no nucleus or membrane-bound organelles. What type of cell is it?

Prokaryotic

A cell contains a nucleus, mitochondria, and Golgi apparatus. What type of cell is it?

Eukaryotic

Which type of eukaryotic cell contains chloroplasts?

Plant cells

Which type of eukaryotic cell contains a cell wall?

Plant cells

Which type of eukaryotic cell contains a large central vacuole?

Plant cells

Which type of eukaryotic cell contains centrosomes according to the course material?

Animal cells

Which type of eukaryotic cell contains lysosomes according to the course comparison?

Animal cells

A eukaryotic cell has a cell wall, chloroplasts, and a large central vacuole. What type of cell is it?

Plant cell

A eukaryotic cell has centrosomes but no chloroplasts or cell wall. What type of cell is it?

Animal cell

True or False: Plant and animal cells have completely different organelles.

False. They share many organelles, but each has some structures that the other does not.

Name three structures that plant cells have that animal cells do not.

Cell wall, chloroplasts, and central vacuole.

An organelle consists of stacks of flattened membranes. What is it?

Golgi apparatus

An organelle has an outer membrane and a highly folded inner membrane. What is it?

Mitochondrion

An organelle has ribosomes attached to its surface, giving it a rough appearance. What is it?

Rough ER

An organelle is involved in lipid synthesis and lacks attached ribosomes. What is it?

Smooth ER

A structure contains DNA and associated proteins called chromatin and is surrounded by a nuclear envelope. What is it?

Nucleus

A structure contains a region where ribosomes are synthesized. What is it?

Nucleolus

A structure consists of two layers of phospholipids with embedded proteins. What is it?

Plasma membrane