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)
