Bio 183

Which of the following statements is true about functional groups?

Function groups are found in amino acids Functional groups exhibit similar properties in all molecules in which they are found

Which of the following roles is NOT commonly performed by proteins?

Linking of nucleotides between the 2 strands of the DNA double helix

Isomers

molecules with same molecular formula

Which of the following structures would least likely be found as part of a bacterium?

neither lysosome or golgi apparatus

The average intracellular voltage of most cells in the human body varies between which two values

-5 to -100 millivolts

Protein structure (1-4)

1. linear sequence of amino acids 2. hydrogen boding within peptide backbone 3. 3-dimensional shape of polypeptide chain 4. assembly of subunits into functional protein

The flagella of eukaryotes are composed of microtubules, whereas the flagella of bacteria are made of ____________________.

9+2 arrangement microtubules

The plasma membrane is best described as

A double membrane of phospholipids arranged in a fluid-mosaic of lipids, proteins, and carbohydrates

Which of the following best describes the basic structure of a nucleotide?

A phosphate group, a pentose sugar, and a nitrogenous base

The smooth endoplasmic reticulum is involved primarily in which of the following? A. Calcium storage, detoxification, and steroid synthesis B. Protein packaging C. Nucleotide synthesis D. Energy production E. Macromolecules hydrolysis

A. Calcium storage, detoxification, and steroid synthesis

In an attempt to temporarily store isolated red blood cells collected from a seal (mammal), Billy Bob, the marine scientist places these cells in a beaker of sea water at body temperature (37 degrees C). When attempting to retrieve his cells a couple of hours later, all the scientist can find are a bunch of small particles that resemble cell debris. Which of the following is the most likely explanation of Billy Bob's failed experiment? A. The cells were placed in a hypertonic solution and crenated B. The cells were placed in a hypotonic solution and crenated C. The cells were placed in a hypertonic solution and lysed D. The cells were placed in a hypotonic solution and lysed E. Seals don't have red blood cells

A. The cells were placed in a hypertonic solution and crenated

Which of the following best describes the movement of small polar ions such as Na^+, Cl^-, K^+ and Ca2^+ across a simple cell membrane made exclusively of phospholipids? A. The membrane is totally impermeable to those ions B. The membrane allows the movement of NA^+ and K^+, but not other ions C. The membrane is totally permeable to small polar ions D. The membrane allows the movement of small polar ions only if both sides of the membrane are isotonic E. The membrane is permeable to small polar ions only if they are dissolved in water

A. The membrane is totally impermeable to those ions

The rough endoplasmic reticulum is involved primarily in which of the following? A.Protein synthesis, folding and sorting B. Lipid assembly C. Synthesis of ATP D. Breaking down of macromolecules E. Making ribosomes

A.Protein synthesis, folding and sorting

Which statement about ATP is correct

ATP serves as a main energy source inside the cell

In skeletal muscles, calcium pups hydrolyze ATP in order to transport calcium against its concentration gradient, from the cytosol into the sarcoplasmic reticulum ( a specialized form of endoplasmic reticulum). This is an example of

Active transport

The cytoskeleton is composed of which of the following (in order, from small to large size) A. proteins, small bones and cartilage B. Actin filaments, microfilaments, and intermediate filaments C. Microtubules, intermediate filaments, and actin filaments D. Actin filaments, intermediate filaments, and microtubules E. Flagella, microtubules, and actin filaments

Answer: Actin filaments, intermediate filaments and microtubules

In plant cells, most of the ATP to be used by the cell is produced by which of the following? A. the smooth endoplasmic reticulum B. Chloroplasts C. the rough endoplasmic reticulum d. Mitochondria E. None of the above

Answer: Mitochondria

The average intracellular voltage of most cells in human body varies between which two values? A. -500 to -1000 volts B. -5 to -100 millivolts C. 5 to 100 megavolts D. -5 to -100 volts E. -70 millivolts

B. -5 to -100 millivolts

The plasma membrane is best described as A. A double layer of proteins that is impermeable to water, but allows free movement of ions B. A double membrane of phospholipids arranged in a fluid-mosaic of lipids, proteins and carbohydrates C. A stiff double membrane composed of phospholipids, proteins and nucleic acids D. A double layer made entirely of glycoproteins, glycolipids and cholesterol E. None of the above

B. A double membrane of phospholipids arranged in a fluid-mosaic of lipids, proteins and carbohydrates

All of the following plasma membrane activities require energy from ATP hydrolysis, except A. The activation of the Na^+/K^+ pump B. Facilitated diffusion C. Active transport D. Activation of a flagellum E. Neither B nor D requires ATP hydrolysis

B. Facilitated diffusion

The presence of cholesterol in the plasma membrane does which of the following? A. It makes the membrane more fluid at low temperatures B. It makes the membrane stiffer at low temperature C. Cholesterol does not affect the properties of the plasma membrane D. Good cholesterol does not affect the plasma membrane, but bad cholesterol makes it more rigid E. Both A and D are correct

B. It makes the membrane stiffer at low temperature

Which of the following cell connections allows the movement of small ions such as calcium from one cell to another? A. Desmosomes B. Tight junctions C. Gap junctions D. Integrins E. Claudins

C. Gap junctions

In the lungs, oxygen moves freely across the cell membrane of alveoli, down its concentration gradient, and without the requirement of any carrier protein or any input of external energy. This is an example of A. Primary Active transport B. Osmosis C. Passive diffusion D. Facilitated diffusion E. Phagocytosis

C. Passive diffusion

Protein structures that help other proteins fold properly are called ________________.

Chaperones

Which of the following polysaccharides are you most likely to find in the exoskeleton of a locust?

Chitin

The endoplasmic theory suggests that

Chloroplasts and mitochondria are thought to have originated from free-living unicellular organisms

The cytoskeleton is composed of which of the following (in order from small to large size) A. Proteins, small bones, cartilage B. Actin filaments, microfilaments, intermediate filaments C. Microtubules, intermediate filaments, actin filaments D. Actin filaments, intermediate filaments, microtubules E. Flagella, microtubules, actin filaments

D. Actin filaments, intermediate filaments, microtubules

Which of the following factors does NOT affect membrane fluidity? A. The length of fatty acyl chains B. The presence of double bonds in the fatty acyl chains C. Presence of cholesterol D. Presence of glycoproteins E. Temperature changes

D. Presence of glycoproteins

The Golgi apparatus is primarily involved in A. mRNA degradation B. Linking lysosomes with old organelles C. Docking vesicles with the plasma membrane D. Protein processing, sorting, and secretion E. Both B and D are correct

D. Protein processing, sorting, and secretion

The function of major histocompatibility complexes (MHC) in the cell membrane is A. Transport of ions across the membrane B. Anchoring of cells to the extracellular matrix C. To form gap junctions D. To provide cellular identification (By the immune system, for instance) E. To allow the flipping of phospholipids between the 2 membrane leaflets

D. To provide cellular identification (By the immune system, for instance)

What is/are the main differences between DNA and RNA?

DNA is double-stranded while RNA is single stranded

Which of the following factors have the ability to denature a protein, thereby affecting its functionality? A. Wrong temperature B. Wrong pH C. Enzymes are very resilient structures that cannot be denatured D. Wrong salt concentration E. A, B and D are correct

E. A, B and D are correct

Which of the following is not a polysaccharide? A. Glycogen B. Chitin C. Starch D. Cellulose E. All of the above are polysaccharides

E. All of the above are polysaccharides

The hydrolysis of macromolecules and organelles that are no longer needed in the cells is most likely to take place in which of the following? A. Microbodies (peroxisomes) B. Lysosomes C. Endoplasmic reticulum D. Golgi apparatus E. Both A and B are involved in macromolecule and organelle degradation

E. Both A and B are involved in macromolecule and organelle degradation

The main difference between active and passive transport across a cell membrane is A. Active transport requires channels while passive transport does not B. Active transport requires transport proteins while passive transport does not C. Active transport requires energy while passive transport does not D. Active transport involves the movement of molecules against their concentration gradient E. Both C and D are correct

E. Both C and D are correct

The endosymbiotic theory suggests that A. Chloroplasts and mitochondria always work together B. Plant and animal cells evolved together C. Eukaryotes evolved separately from prokaryotes D. Prokaryotes and eukaryotes contain similar organelles E. Chloroplasts and mitochondria are thought to have originated from free-living unicellular organisms

E. Chloroplasts and mitochondria are thought to have originated from free-living unicellular organisms

In eukaryotic cells, most of the ATP is produced by which of the following? A. The smooth endoplasmic reticulum B. The Golgi apparatus C. The rough endoplasmic reticulum D. Microbodies E. None of the above

E. None of the above

Two molecules that have identical molecular formulas but look like mirror images of each other are known as

Enantiomers

Some bacteria have the to temporarily develop a thick wall around their genome and a small portion of the cytoplasm, making them highly resistant to environmental stress. These temporary structures are called ________________.

Endospores

Which of the following cell connections allows the movement of small ions such as calcium from one cell to another?

Gap junctions

Sucrose (table sugar) is a disaccharide compose of

Glucose and fructose

Starch is converted into monosaccharides during a process known as

Hydrolysis

Which of the following structures allows cells to "read" the extracellular matrix and be influenced by it?

Integrins

Which of the following is true regarding your mitochondria DNA

It is almost identical to your mothers mitochondrial DNA & It is virtually identical in all the cells of your body

Enzymes catalyze chemical reactions by

Lowering the activation energy necessary to start the reaction

When placed in water, phospholipids tend to spontaneously arrange themselves in spherical structures known as

Micelles

Which of the following factors contribute significantly to high membrane fluidity?

Presence of double bonds in the fatty acyl chains

Proportionally to its volume, a bear has a surface area that is smaller or larger than a mouse.

Smaller

Which of the following statements is false regarding DNA and RNA?

The 2 purines found in DNA are adenine and cytosine

What could be said about a tomato skin cell that is placed in deionized water for an extended period of time

The cell is placed in hypotonic environment is likely to lyse

If you discovered a new protein made of a series of alpha-helical motifs attached back to back. What would this information suggest to you?

The protein is likely to be found embedded in some membrane

The liver is heavily involved in detoxifying the blood? Based on this statement, which of the following characteristic would you expect to best describe hepatocytes = liver cells

Very large smooth endoplasmic reticulum

Purines

adenine and guanine

Chain of events (smallest to largest)

amino acid-->peptide--> polypeptide--> protein

Which of the following is/are a monosaccharide? a. sucrose b. lactose c. fructose d. cellulose

answer: Fructose

The outer structure of Gram positive bacteria is made mainly of A. polysaccharides B. Cellulose C. Chitin D. Proteins E. Proteoglycan

answer: Proteoglycan

Which of the following structures/molecules would least likely be found in/on a bacterium A. DNA B. Chloroplast C. Cell wall D. Ribosomes E. Neither A nor C

answer: chloroplast

Structural isomers

are molecules which have the same molecular formula but have different connectivities

Would a small hydrophilic molecule most likely to be found INSIDE the cell membrane or ATTACHED TO ITS SURFACE

attached to its surface

In the endomembrane system, proteins that are polymerized and inserted in the ER lumen are then transported to the ________-side of the Golgi apparatus.

cis

Triglyceride

composed of 1 glycerol and 3 fatty acids

Stereoisomers

differ in how groups are attached

Match the level of protein structure on the left with the appropriate description on the right. i. Primary ii. Secondary iii. Tertiary iv. Quaternary w. 3-dimensional shape of polypeptide chain x. linear sequence of amino acids y. assembly of subunits into functional protein z. hydrogen bonding within peptide backbone (ex:α-helix)

i=x, ii=z, iii=w, iv=y

Which of the following is accurate regarding the disaccharide lactose?

lactose is composed of galactose and glucose/Lactose is a sugar found in milk and some of its derivatives

Hydrophilic

likes water

In eukaryotes, endocytosed solid particles are broken into smaller subunits by

lysosomes

The process by which cells intake small solid particles (as opposed to liquid ones) is known as ______________________

phagocytosis

Hydrophobic

scared of water

Hypertonic

shrinks cell- has higher solute concentration (crenation)

Hypotonic

swells cell- solution has a lower solute (lysis)

pyrimidines

thymine (only in DNA) cytosine, uracil (only in RNA)