Chapter 6: A Tour of the Cell

The endoplasmic reticulum is part of the endomembrane system, which also includes the __________.

nuclear envelope, the Golgi apparatus, lysosomes, and vesicles

The region of a bacterial cell that contains the genetic material is called the __________.

nucleoid

You would expect a cell with an extensive Golgi apparatus to __________.

secrete a lot of protein

Vacuole

storage of water, carbohydrates, pigments

Microfilaments function in cell motility including __________.

muscle contraction, amoeboid movement, and cytoplasmic streaming in plants.

Mitochondria

ATP production

Chromatin

Bacteria

Peroxisomes

Breakdown toxins like hydrogen peroxide; Breakdown of fatty acids

Eukaryotic Cell

Condensed Chromatin

Chromosomes

Contains organelles

Lysosomes

Digests macromolecules and recycling

In terms of cellular function, what is the most important difference between prokaryotic and eukaryotic cells?

Eukaryotic cells are compartmentalized, which allows for specialization.

Cytoplasm

Internal space of the cell holds all the cellular structures

Smooth ER

Lipid synthesis and detoxification of drugs

Nucleus

Location of genomic DNA, location of ribosome assembly

Flagella and Cilia

Movement

__________ are membrane-bound metabolic compartments that specialize in the production of hydrogen peroxide (H2O2) and its conversion to water.

Peroxisomes

Chloroplast

Produces sugar and ATP by photosynthesis

Cell Wall

Protection and Structural Support

Nucleolus

Protein Synthesis

Ribosome and Rough ER

Protein Synthesis

Ribosomes

Protein and DNA

Prokaryotic cell

Protein and rRNA

Golgi apparatus

Protein processing (modification and packaging)

Plasma membrane

Selective Permeability-maintains internal environment

Cytoskeleton

Structural Support; movement of material; or movement of whole cell

What is the functional connection between the nucleolus, nuclear pores, and the nuclear membrane?

Subunits of ribosomes are assembled in the nucleolus and pass through the nuclear membrane via the nuclear pores.

Your intestine is lined with individual cells. No fluids leak between these cells from the gut into your body. Why?

The intestinal cells are bound together by tight junctions.

Which of the following is false in respect to cells' chromosomes? a. Chromosomes are only visible as a cell is about to divide. b. Chromosomes contain DNA and proteins. c. Chromosomes are present throughout a cell's reproductive cycle. d. Chromosomes exist even when cells are not actively synthesizing proteins.

a. Chromosomes are only visible as a cell is about to divide.

Basal bodies are most closely associated with which of the following cell components? a. Cilia b. Nucleus c. Mitochondria d. The central vacuole e. Golgi apparatus

a. Cilia

Which statement about the cytoskeleton is true? a. Components of the cytoskeleton often mediate the movement of organelles within the cytoplasm. b. Intermediate filaments are hollow tubes of protein that provide structural support. c. Microtubules are chains of proteins that resist stretching. d. Microfilaments are more permanent structures in cells compared to intermediate filaments and microtubules. e. Plant cells lack a cytoskeleton because they have a rigid cell wall.

a. Components of the cytoskeleton often mediate the movement of organelles within the cytoplasm.

Cilia and flagella move due to the interaction of the cytoskeleton with which of the following? a. Motor proteins b. Actin c. Pseudopodia d. Mitochondria e. Tubulin

a. Motor proteins

Which of the following is present in a prokaryotic cell? a. Ribosomes b. Mitochondrion c. Nuclear envelope d. Chloroplast e. ER

a. Ribosomes

Which of the following groups is primarily involved in synthesizing molecules needed by the cell? a. Ribosomes, rough endoplasmic reticulum, and smooth endoplasmic reticulum. b. Lysosome, vacuole, and ribosomes. c. Vacuole, rough endoplasmic reticulum, and smooth endoplasmic reticulum. d. Smooth endoplasmic reticulum, ribosomes, and vacuole. e. Rough endoplasmic reticulum, lysosome, and vacuole.

a. Ribosomes, rough endoplasmic reticulum, and smooth endoplasmic reticulum.

The extracellular matrix of the animal cell has all of the following molecular components except __________. a. a middle lamella b. collagen c. proteoglycans d. fibronectin e. integrins

a. a middle lamella

Evidence that supports the prokaryotic origins of mitochondria and chloroplasts are all of the following except __________. a. that mitochondria and chloroplasts have multiple copies of linear DNA molecules associated with their inner membranes. b. that the ancestral prokaryote had two outer membranes, which became the double membranes of the mitochondria and chloroplasts. c. that mitochondria and chloroplasts have multiple copies of circular DNA molecules associated with their membranes. d. that mitochondria and chloroplasts can grow and reproduce within a cell. e. that mitochondria and chloroplasts are somewhat independent within a cell.

a. that mitochondria and chloroplasts have multiple copies of linear DNA molecules associated with their inner membranes.

Which of these structures are not found in plant cells? a. mitochondria b. centrioles c. microtubules d. all of the above choices are correct e. none of the above choices are correct

b. centrioles

The Golgi ____________. a. is the site for glycogen degradation in animal cells. b. concentrates, packages, and sorts proteins. c. contains thylakoids. d. contains cristae. e.noneof the above choices are correct.

b. concentrates, packages, and sorts proteins.

The mitochondria is the site of ____________. a. protein synthesis b. lipid synthesis c. ATP synthesis d. glycogen breakdown e. all of the above choices are correct

c. ATP synthesis

Which of the following statements about microscopes is not true? a. Electron microscopes have greater image resolution than light microscopes. b. Cells examined by electron microscopy are dead. c. Both electron and light microscopes can visualize many viruses. d. Bright-field microscopy often offers little contrast. e. None of the above choices are correct.

c. Both electron and light microscopes can visualize many viruses.

Food molecules enter the cells through a process called ____________. a. autophagy b. cellular respiration c. phagocytosis d. none of the above choices are correct e.all ofthe above choices are correct

c. phagocytosis

The organelle that is a plant cell's compartment for the storage of inorganic ions such as potassium and chloride is the __________.

central vacuole

Animal cells have unique organelles called __________ that are composed of structures called __________.

centrosomes; centrioles

This structure packages and sorts proteins. a. Cilia b. Flagella c. Vacuoles d. The Golgi apparatus e. All of the above choices are involved in the packaging and sorting of proteins

d. The Golgi apparatus

Which statement about ribosomes is correct? a. They are complexes of DNA and proteins. b. They can be visualized under a light microscope. c. They are found only in eukaryotic cells. d. They are the sites of protein synthesis. e. None of the above choices are correct.

d. They are the sites of protein synthesis.

Smooth endoplasmic reticulum ____________. a. does not contain ribosomes b. synthesizes lipids c. modifies small molecules d. all of the above choices are correct e. none of the above choices are correct

d. all of the above choices are correct

Lysosomes contain ______________. a. DNA b. hydrolytic enzymes c. ATP d. digestive enzymes e. choices b and d are both correct

e. choices b and d are both correct

Bacterial cells are prokaryotic. Unlike a typical eukaryotic cell they __________.

have no membrane-bounded organelles in their cytoplasm

Observing a fluorescent micrograph cell with intermediate filaments would help you identify the cell as a __________.

human skin cell

A protein that ultimately functions in the plasma membrane of a cell is most likely to have been synthesized __________.

in the rough endoplasmic reticulum

The walls of plant cells are largely composed of polysaccharides and proteins that are synthesized __________.

in the rough endoplasmic reticulum and in the Golgi apparatus

The network of fibers that organizes structures and activities in a cell __________.

is the cytoskeleton

The endosymbiont theory explains the origins of __________.

mitochondria and chloroplasts

Cells are small because __________.

of the geometric relationships between surface and volume

Dye injected into a plant cell might be able to enter an adjacent cell through __________.

plasmodesmata

Cell junctions in plant cells are called __________, and communicating junctions in animal cells are called __________.

plasmodesmata; gap junctions

A substance moving from outside the cell into the cytoplasm must pass through __________.

the plasma membrane

The function of the rough endoplasmic reticulum (RER) is __________.

to synthesize proteins that are secreted as glycoproteins

Cell motility, which includes changes both in cell location and in the movement of cell parts, requires interactions of the cytoskeleton __________.

with motor proteins