Cells and Organelles

Which of the following is an example of integral proteins?

A. adhesion proteins

B. cellular recognition proteins

C. transport proteins

C

• Integral/transmembrane proteins

  • transport proteins

  • integral receptor proteins

What type of membrane protein are receptor proteins?

A. they can be either integral or peripheral membrane proteins

B. they are only integral membrane proteins

C. they are only peripheral membrane proteins

A

What type of ligand binds to a receptor protein and activates its response?

A. antagonists

B. agonists

C. transcripts

D. secondary messengers

B

Which of the following is true regarding passive diffusion?

A. molecules diffuse down a concentration gradient

B. requires input of energy

C. it is a subcategory of active transport

A

All of the following are characteristics of active transport EXCEPT one. Which is the EXCEPTION?

A. particles travel against their concentration gradient

B. requires an input of energy

C. can be divided into primary or secondary active transport

D. primarily involves ion channels

D

• relies upon carrier proteins that change their shape, not ion channels

Which of the following releases material to the extracellular environment through vesicle secretion?

A. exocytosis

B. phagocytosis

C. pinocytosis

D. receptor-mediated cytosis

A

• the rest are forms of endocytosis

Where is rRNA produced?

A. nucleolus

B. mitochondria

C. nucleoplasm

D. cytoplasm

A

• rRNA is produced/transcribed in the nucleolus

What are the components of a ribosomal subunit?

A. rRNA and DNA

B. rRNA and proteins

C. DNA and proteins

B

• the proteins enter the nucleoplasm (from the cytosol) via nuclear pores, and rRNA synthesis occurs via transcription within the nucleolus

What structure is continuous with the outer membrane of the nuclear envelope?

A. mitochondria

B. rough ER

C. smooth ER

D. golgi apparatus

B

Which process involves the modification of proteins with carbohydrates?

A. glycosylation

B. carboxylation

C. phosphorylation

D. acetylation

A

• glycosylation modifies proteins that enter the rough ER lumen by attaching carbohydrates to the protein

• the modified proteins will then move toward the Golgi for packaging

Which organelle is responsible for breaking down substances using acidic hydrolytic enzymes?

A. peroxisomes

B. lysosomes

C. smooth ER

D. golgi apparatus

B

Which of the following organelles is a part of the endomembrane system?

A. mitochondria

B. chloroplasts

C. peroxisomes

D. lysosomes

D

• endomembrane system

  • nucleus

  • rough ER

  • smooth ER

  • golgi

  • lysosomes

  • vacuoles

  • vesicles

  • cell membrane

Which enzyme do peroxisomes contain to break down excess hydrogen peroxide?

A. transferase

B. hydrolase

C. superoxide dismutase

D. catalase

E. reductase

D

• catalase convers hydrogen peroxide into water

Which of the following is NOT a function of microfilaments?

A. cytoplasmic streaming

B. form cilia and flagella

C. muscle contraction

D. cleavage furrow

B

• microtubules form cilia and flagella

All of the following processes directly involve microtubules EXCEPT one. Which one is the EXCEPTION?

A. muscle contraction

B. cell division

C. production of cilia

D. production of flagella

A

• microfilaments play a critical role in muscle contraction

Which type of tissue forms glands and lines internal cavities and organs?

A. nervous

B. muscular

C. epithelial

D. connective

C

Which two cytoskeletal elements have an active role in cell division?

A. microfilaments and intermediate filaments

B. microfilaments and microtubules

C. intermediate filaments and microtubules

B

Which of the following cells do NOT have cell walls?

A. animals

B. plants

C. fungi

D. archaea

E. bacteria

A

• cell walls overlie the cell membrane in plants, fungi, bacteria, and archaea

In which environment would water leave the cell via osmosis?

A. isotonic

B. hypertonic

C. hypotonic

B

• if the solute conc. outside a cell were higher, it would be a hypertonic environment

• water moves from low to high solute conc., so it would move outside the cell

• if a cell in a hypertonic environment has a cell wall (like a plant cell), the cell membrane will dehydrate/shrink away from the cell wall during plasmolysis

In which environment would a cell with a cell wall undergo plasmolysis?

A. isotonic

B. hypertonic

C. hypotonic

B

• plasmolysis is when water leaves the cell

Which process do lipid soluble molecules most likely use to cross the plasma membrane?

A. active transport

B. endocytosis

C. osmosis

D. secondary active transport

E. simple diffusion

E

• cell membrane has a high lipid content, so lipid-soluble materials directly cross the cell membrane via simple diffusion

Which of the following would occur if a red blood cell is placed in distilled water?

A. burst

B. shrivel

C. slightly swell

D. no change

A

• distilled water contains no solutes, it is pure H2O

• red blood cell contains many solutes

• water will move from low to high solute conc, so into the cell, causing it to burst

Which of the following organelles would be affected if the process of protein glycosylation was inhibited?

A. mitochondria

B. ribosome

C. cytoplasm

D. golgi apparatus

E. nucleus

D

• glycosylation (binding a carbohydrate to a protein) is a post-translational modification, it happens after the production of the protein

• glycosylation occurs in the rough ER and the Golgi, so those two places would be affected

Insulin is a hormone that increases the number of GLUT4 transporters in a cell. Which of the following processes do these transporters use to shuttle glucose across cell membranes?

A. clathrin-mediated endocytosis

B. exocytosis

C. facilitated diffusion

D. pinocytosis

E. secondary active transport

C

Which of the following would you expect to find the LEAST amount of in the cell membrane?

A. proteins

B. carbohydrates

C. DNA

D. phospholipids

C

• cell membrane is mostly composed of phospholipids and proteins

• carbohydrates are found in much lower levels

• DNA is not a component of the cell membrane

Which of the following describes a marine fish relative to its saltwater environment?

A. entropic

B. hypertonic

C. hypotonic

D. isotonic

E. osmotic

C

• a saltwater fish is less salty than the concentrated saltwater surrounding it, so it will constantly lose water to the environment

• to make up for this, they must constantly drink water, rarely urinate, and secrete salts

Proteins that will be secreted are first translated in the ________ and then transported to the ________ for secretion.

A. nucleus, Golgi

B. mitochondria, lysosome

C. ribosome, nucleus

D. endoplasmic reticulum, Golgi

E. cytoplasm, mitochondria

D

A sample of cells is placed in a 3.4% salt solution. The cells are observed to become smaller and wrinkled in shape due to water loss. Which of the following does this indicate?

A. the cells are hypotonic to the 3.4% salt solution

B. the cells are hypertonic to the 3.4% salt solution

C. the cells are isotonic to the 3.4% salt solution

A

Which of the following is the smallest in size?

A. ribosome

B. nucleus

C. golgi body

D. chloroplast

E. mitochondria

A

Which of the following is derived from cholesterol?

A. adenine

B. triglyceride

C. pepsin

D. testosterone

E. vitamin K

D

• cholesterol is a precursor to most steroid hormones, including all the sex hormones

• it is also the starting material for vitamin D and bile acids

A researcher identifies a protein of interest and notes that it contains a hydrophobic region. Which of the following is it most likely to be?

A. cytoplasmic protein

B. histone

C. lipid molecule

D. transmembrane protein

E. tRNA

D

Which of the following are found in eukaryotic plasma membranes but NOT in prokaryotic plasma membranes?

A. steroids

B. vitamins

C. phospholipids

D. cellulose

E. glycolipids

A

Which of the following is associated with receptor-mediated endocytosis?

A. clathrin

B. dynein

C. fibronectin

D. integrin

E. tubulin

A

Which of the following would occur if the Na⁺/K⁺ ATPase was inactivated?

A. decrease in extracellular K+ conc.

B. decrease in intracellular Na+ conc.

C. increase in extracellular K+ conc.

D. increase in extracellular Na+ conc.

C

• pumps Na out

• pumps K into

All of the following are true of centrioles EXCEPT one. Which is the EXCEPTION?

A. composed of microtubules

B. found in all eukaryotic cells

C. lack a membrane

D. organize the spindle apparatus

E. form a centrosome when paired

B

• centrioles are only found in animal cells

Each of the following structures is associated with locomotion EXCEPT one. Which is the EXCEPTION?

A. flagella

B. pseudopodia

C. microfilaments

D. striated muscle

E. contractile vacuoles

E

• contractile vacuoles are found in single-cell organisms and work to actively pump out excess water, they are not involved in cell locomotion

• *striated muscle enables the movement of bones

All of the following structures are a part of the endomembrane system EXCEPT one. Which is the EXCEPTION?

A. ER

B. central vacuoles

C. mitochondria

D. Golgi

E. plasma membrane

C

Which of the following best describes the function of microfilaments?

A. they function in different types of cell movement

B. they maintain the structural integrity of chromosomes

C. they form basal bodies

D. they function as molecules that store information

E. they generate membrane potentials

A

Which of the following is produced in the smooth endoplasmic reticulum?

A. proteins

B. hydrolytic enzymes

C. lipids

D. vacuoles

E. rRNA

C

• smooth ER synthesizes lipids, including steroid hormones

All of the following structures can be found in animal cells EXCEPT one. Which is the EXCEPTION?

A. peroxisomes

B. centrosomes

C. flagella

D. plastids

E. vacuoles

D

• plastids are found in photosynthetic eukaryotic cells (plants and algae)

All of the following eukaryotic organelles contain a membrane EXCEPT one. Which is the EXCEPTION?

A. mitochondria

B. ER

C. centrioles

D. lysosome

E. Golgi complex

C

• centrioles are the only organelles in eukaryotes that do not contain a membrane

• only animal cells contain centrioles