HW-1: The Cell

Which of these organelles produces H2O2 as a by-product?

peroxisome

Which cell would be best for studying lysosomes?

phagocytic white blood cell

Based on these data, what is the most likely function of the cells in this experiment?

phagocytosis

The _____ is a selective barrier, regulating the passage of material into and out of the cell.

plasma membrane

Identify the path a secretory protein followed from synthesis to secretion.

protein synthesis -- endoplasmic reticulum --> cis golgi cisternae --> medial Golgi cisternae --> trans Golgi cisternae --> plasma membrane -- extracellular space

The _____ is composed of DNA and protein.

chromatin

Which of the following is present in a prokaryotic cell?

ribosome

In the fractionation of homogenized cells using differential centrifugation, which of the following will require the greatest speed to form pellets at the bottom of the tube?

ribosomes

Which of these organelles manufactures proteins bound for secretion out of the cell?

rough endoplasmic reticulum

The cilia and flagella of eukaryotic cells are composed of _____.

microtubules

Which of these are hollow rods that shape and support the cell?

microtubules

Which of the following choices correctly matches a tool and its proper application?

cell fractionation to study the function of specific organelles

Cyanide binds to at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide will be found within the

mitochondria

Which of these organelles carries out cellular respiration?

mitochondrion

Which structure is common to plant and animal cells?

mitochondrion

Where is a bacterial cell's DNA found?

nucleoid region

Ribosomal subunits are manufactured by the _____.

nucleolus

A defect in which of the following intercellular junctions would allow partially digested material to leak passively between the cells of the small intestine into the abdominal cavity?

tight junctions

Which of these cell junctions form a barrier to the passage of materials?

tight junctions

Beginning within the nucleus, the first step leading to the synthesis of a polypeptide is _____.

transferring of information from DNA to messenger RNA

All proteins are synthesized by ribosomes in the cell. Some ribosomes float freely in the cytosol, while others are bound to the surface of the endoplasmic reticulum. Most proteins made by free ribosomes function in the cytosol. Proteins made by bound ribosomes either function within the endomembrane system or pass through it and are secreted from the cell. Which of the following proteins are synthesized by bound ribosomes? Select all that apply.

- ER Protein - lysosomal enzyme - insulin

Which statements are true for chloroplasts? Select the three that apply.

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

The diameter of a typical eukaryotic cell is approximately ten times the diameter of a typical prokaryote. What is the ratio of the volume of typical eukaryotic:prokaryotic cells?

1000:1

Which of the following are common traits of chloroplasts and mitochondria?

Both have their own DNA.

_____ are the sites of protein synthesis.

ribosomes

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 options best depicts the flow of information when a gene directs the synthesis of a cellular component?

DNA → RNA → protein

Select the correct statement describing cellular structure or function.

Plant and animal cells both carry out cellular respiration, producing ATP.

Drag each cell structure to the appropriate bin:

Plant cell only: - chloroplast - cellulose cell wall - central vacuole Animal cell only: - centriole Both: - plasma membrane - cytoskeleton - mitochondrion - golgi apparatus - endoplasmic reticulum - nucleus

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

The ______ is the bacterial structure that acts as a selective barrier, allowing nutrients to enter the cell and waste to leave the cell.

Plasma membrane

What is a function of a bacterium's capsule?

Protection

One difference between eukaryotic and prokaryotic cells is that eukaryotic cells:

have membrane-enclosed organelles, which are lacking in prokaryotic cells.

An animal cell with definite structures labeled from A to E. The vesicles with solid particles inside are labeled A. The vesicles with no solid matter inside are labeled B. The large membrane-bound organelle is labeled C. It is located in the center of the cell and contains a mass of densely stained granules and fibers. The structure labeled D consists of flattened membranous-like stacks. The tiny dots labeled E are located everywhere in the cell and do not have any membrane. Choose the letter that indicates the organelle that contains most of a cell's DNA.

C

Where is calcium stored?

smooth endoplasmic reticulum

Complete the sentences:

1. In eukaryotic flagella, the fibers that slide past one another due to the activity of dyne proteins are microtubules. 2. Many cell organelles, most notably the nucleus, are anchored by intermediate 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 microfilaments. 5. The only cytoskeletal fibers not associated with intracellular movement or whole cell locomotion are the intermediate filaments. 6. During muscle contractions, myosin motor proteins move across tracks of microfilaments.

Complete the sentences

1. The genetic information housed within the nucleus is associated with the protein and is called chromatin. 2. The nuclear envelope is a double membrane that separates the nucleus from the cytoplasm. 3. The synthesis and assembly of ribosomal components occurs in the nucleolus. 4. The shape of the nucleus is maintained by the network of protein filaments called the nuclear lamina. 5. Before RNA can be translated into protein, it first must be exported from the nucleus through a nuclear pore.

An animal cell with definite structures labeled from A to E. The structure labeled A consists of flattened membranous-like stacks. Thin long filaments near the cell surface are labeled B. Vesicles with solid particles inside are labeled C. The membrane network near the nucleus is labeled D. It is connected with the nucleus membrane. This membrane forms small vesicles that are labeled E. Which of these structures stores, modifies, and packages products?

A

A bacterial cell. Each letter marks a definite structure. (A) marks the outer cell envelope. (B) marks numerous short filiform structures on the cell surface. (C) marks a layer of the cell, which is located between the cytoplasm and the cell wall. (D) marks a filiform structure, which forms a globule in the cytoplasm. (E) marks a long filiform process on one side of the cell. The structure that regulates the passage of material into and out of this bacterial cells is indicated by the letter_______.

C) marks a layer of the cell, which is located between the cytoplasm and the cell wall.

An animal cell with definite structures labeled from A to E. The long fibril outside the cell connected with its surface is labeled A. The membrane network near the nucleus is labeled B. It is connected with the nucleus membrane. Tiny dots that are labeled C are located everywhere in the cell and do not have any membrane. Thin long filaments near the cell surface are labeled D. Vesicles with solid particles inside are labeled E. which of these provides the cell with structural support?

D

A bacterial cell. Each letter marks a definite structure. (A) marks the outer cell envelope. (B) marks numerous short filiform structures on the cell surface. (C) marks a layer of the cell, which is located between the cytoplasm and the cell wall. (D) marks a filiform structure, which forms a globule in the cytoplasm. (E) marks a long filiform process on one side of the cell. The DNA-containing region of this bacterial cell is indicated by the letter________.

D) marks a filiform structure, which forms a globule in the cytoplasm

An animal cell with definite structures labeled from A to E. The vesicles with solid particles inside are labeled A. The vesicles with no solid matter inside are labeled B. The large membrane-bound organelle is labeled C. It is located in the center of the cell and contains a mass of densely stained granules and fibers. The structure labeled D consists of flattened membranous-like stacks. The tiny dots labeled E are located everywhere in the cell and do not have any membrane. Which of these is the double membrane that encloses the nucleus?

E

______ are surface appendages that allow a bacterium to stick to a surface.

Fimbriae

_____ aid in the coordination of the activities of adjacent animal cells.

Gap (communicating) junctions

Which statement correctly describes an endomembrane function?

Products of the ER are usually modified during their transit from the cis to the trans region of the Golgi apparatus.

Drag each cell structure to the appropriate bin:

Prokaryotic Only: - Nucleoid Eukaryotic Only: - Nucleolus - Lysosome - Mitochondria Both: - Plasma membrane - Ribosomes - Flagella

Through which pathway do proteins move out of the cell to the extracellular matrix?

Rough ER --> Golgi --> Plasma membrane

Drag each function to the appropriate bin:

Smooth ER: - lipid synthesis - calcium ion storage - poison detoxification Rough ER: - protein synthesis Golgi Apparatus: - protein modification and sorting - cisternal maturation Lysosomes: - macromolecule digestion - autophagy

Choose the best description of the cell cytoskeleton.

The cell cytoskeleton is a dynamic network of fibers that can be quickly dismantled and reassembled to change cell shape and the position of cell components.

Identify the correct statement about differences between rough and smooth endoplasmic reticulum (ER).

The outer surface of smooth ER lacks ribosomes, whereas the outer surface of rough ER has ribosomes.

A newspaper ad for a local toy store indicates that an inexpensive toy microscope available for a small child is able to magnify specimens nearly as much as the more costly microscope available in your college lab. What is the primary reason for the price difference?

The toy microscope magnifies a good deal, but has low resolution and therefore poor quality images.

The primary role of _____ is to bind animal cells together.

desmosomes

Which of the following clues would tell you if a cell is prokaryotic or eukaryotic?

whether or not the cell is partitioned by internal membranes