Biology Chapter 6

The extracellular matrix of the animal cell has all of the following molecular components except (?)

a middle lamella

Cilia and flagella bend because of

a motor protein called dynein

Can you match these prefixes, suffixes, and word roots with their definitions?

across: trans- between: inter- two: bi- body: -some (or soma-) color: chrom- little, small: -elle water: aqu- (or aqua-) inside, inner: endo- out of: ex- cell: -cyte (or cyto-) green: chloro- thread: mito- without, lack of, not: a- (or an-) true, good: eu- leaf: -phyll same: sym- above, greater than: hyper- below, less than: hypo- formed substance: -plasm eat: phago- small: micro-

All of the following are part of a prokaryotic cell EXCEPT

an endoplasmic reticulum

Basal bodies are most closely associated with which of the following cell components?

cilia

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.

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

eukaryotic cells are compartmentalized, which allows for specialization

Cell size is limited by

surface to volume ratios

Evidence that supports the prokaryotic origins of mitochondria and chloroplasts are all of the following except (?)

that mitochondria and chloroplasts have multiple copies of circular DNA molecules associated with their membranes

Which organelle often takes up much of the volume of a plant cell?

vacuole

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

with motor proteins

In the fractionation of homogenized cells using centrifugation, the primary factor that determines whether a specific cellular component ends up in the supernatant or the pellet is the (?)

size and weight of the component

The cytoskeleton of a eukaryotic cell plays a major role in organizing the structures and activities of the cell. The cytoskeleton consists of three main types of fibers: microfilaments, intermediate filaments, and microtubules. The three types of fiber differ in size, composition, and the functions they perform in the cell.

1. In eukaryotic flagella, the fibers that slide past one another due to the activity of dynein proteins are microtubules. . 2. Many cell organelles, most notably the nucleus, are anchored by intermidiate filaments which are assembled from a diverse class of proteins. 3. Centrosomes are sites where protein dimers assemble into microtubules. 4. The extension of pseudopodia in amoeba is due to the regulated assembly and destruction of microfililaments. 5. The only cytoskeletal fibers not associated with intracellular movement or whole cell locomotion are the intermidiate filaments . 6. During muscle contractions, myosin motor proteins move across tracks of microfililaments.

The cellular organization and extracellular environments of plants and animals are very different.

1. Membrane protein complexes that strengthen the adhesion between adjacent cells, like rivets, to protect against pulling forces structure: desmosomes; animal 2. Small channels that form across the plasma membranes of adjacent cells; especially important in intercellular communication structure: gap junctions; animal 3. Membrane proteins that create a watertight seal between cells structure: tight junctions; animal 4. Small channels between cells that are otherwise surrounded by walls; enable movement of water and solutes between cells structure: plasmodesmata; plant 5. A polysaccharide that is used to synthesize cell walls, which protect cells and help maintain their shape structure: cellulose; plant 6. Long fibers of protein found in the extracellular matrix that provide structural support for cells structure: collagen; animal SEE IMAGE ON FILE (2)

1 meter = _____ centimeters.

100 centimeters

The structure that regulates the passage of material into and out of this bacterial cell is indicated by the letter (?)

C The plasma membrane is selectively permeable.

What name is given to the rigid structure, found outside the plasma membrane, that surrounds and supports the bacterial cell?

Cell Wall

Which of the following is false in respect to cells' chromosomes?

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

Which statement about the cytoskeleton is true?

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

The DNA-containing region of this bacterial cell is indicated by the letter (?)

D The nucleoid region contains DNA.

Which of the following proteins are synthesized by bound ribosomes?

ER protein, lysosomal protein, and insulin

(?) are surface appendages that allow a bacterium to stick to a surface.

Fimbriae

Where is a bacterial cell's DNA found?

Nucleoid region

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

Peroxisomes

Plant cells and animal cells share many of the same structures, but each type of cell also has unique structures. In this activity, you will indicate which cell structures are found only in plant cells, only in animal cells, or in both plant and animal cells.

Plant cell only: - Cellulose cell wall - Chloroplast - Central vacuole Animal cell only: - Centriole Both: - Nucleus - Plasma membrane - Mitochondrion - Cytoskeleton - Endoplasmic reticulum - Golgi apparatus

Drag the correct description under each cell structure to identify the role it plays in the plant cell.

Plant cell wall: - strong, protective structure made from cellulose fibrils Central vacuole: - regulates cytoplasm composition, creates internal pressure, and stores cell compounds Chloroplast: - makes sugar by converting light energy into chemical energy Mitochondrion: - produces chemical energy (ATP) that can power the cell Golgi apparatus: - modifies and packages proteins SEE IMAGE ON FILE (3)

The (?) is the bacterial structure that acts as a selective barrier, allowing nutrients to enter the cell and wastes to leave the cell.

Plasma Membrane

Two fundamental types of cells are known to exist in nature: prokaryotic cells and eukaryotic cells (like the one shown in the Tour of an Animal Cell animation). Both prokaryotic and eukaryotic cells carry out all of the processes necessary for life, but they differ in some important ways. In this activity, you will identify which cell structures are found only in prokaryotic cells, only in eukaryotic cells, or in both types of cells.

Prokaryotic only - nucleoid Eukaryotic only - Lysosome, Mitochondria, Nucleolus BOTH -: Ribosomes, Plasma membrane, Flagella

What is a function of a bacterium's capsule?

Protection

Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules?

Proteins

Beginning within the nucleus, the first step leading to the synthesis of a polypeptide is (?)

Transferring of information from DNA to messenger RNA

In a bacterium, where are proteins synthesized?

Ribosomes

Which of the following groups is primarily involved in synthesizing molecules needed by the cell?

Ribosomes, rough endoplasmic reticulum, and smooth endoplasmic reticulum

The various parts of the endomembrane system serve different functions in the cell. In this activity, you will identify the roles of each part of the endomembrane system.

Smooth ER: lipid synthesis, calcium storage, poison detoxification Rough ER: protein synthesis Golgi apparatus: protein modification and sorting, cisternal maturation Lysosomes: macromolecul digestion, autophagy

Which statements are true for chloroplasts?

They are the sites of reactions that convert solar energy into chemical energy. They contain the green pigment chlorophyll. They have membranous sacs called thylakoids that are surrounded by a fluid called stroma.

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

central vacuole

Which organelle or structure is absent in plant cells?

centrosomes

Animal cells have unique organelles called (?) that are composed of structures called (?)

centrosomes; centrioles

The network of fibers that organizes structures and activities in a cell (?)

cytoskeleton

Proteins that are secreted from a eukaryotic cell must first travel through the endomembrane system.

endoplasmic reticulum, cis Golgi cisternae, medial Golgi cisternae, trans Golgi cisternae, plasma membrane

Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells?

gap junctions

Bacterial cells are prokaryotic. Unlike a typical eukaryotic cell they (?)

have no membrane-bound organelles in their cytoplasm

Observing a fluorescent micrograph cell with intermediate filaments would help you identify the cell as a (?)

human skin cell

In a plant cell, DNA may be found (?)

in the nucleus, mitochondria, and chloroplasts

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 advantage of light microscopy over electron microscopy is that (?)

light microscopy allows one to view dynamic processes in living cells

The endosymbiont theory explains the origins of (?)

mitochondria and chloroplasts

Cilia and flagella move due to the interaction of the cytoskeleton with which of the following?

motor proteins

Microfilaments function in cell motility including (?)

muscle contraction, amoeboid movement, and cytoplasmic streaming in plants

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

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 throug

plasmodesmata

Cell junctions in plant cells are called (?), and communicating junctions in animal cells are called (?).

plasmodesmata; gap junctions

Which of the following is present in a prokaryotic cell?

ribosomes

You would expect a cell with an extensive Golgi apparatus to

secrete a lot of protein

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

Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large, complex, undigested lipids. Which cellular organelle must be involved in this condition?

the lysosome

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