BIOL200 Sample Midterm Exam-KEYS
Chapter 3
1.Chitin is a __________ while testosterone is a _____________
a. Modified carbohydrate; lipid
c. Amino acid; fatty acid
b. Lipid; modified carbohydrate
d. Modified nucleotide; lipid
2.Amino acids are to form proteins while __________ are to form DNA
a. Nucleic acids
c. Monosaccharides
b. Nucleotides
d. Fatty acids
3.The bond between two nucleotides is named
a. Peptide bond
b. Phosphodiester bond
c.
d.
Glycosidic bond
Van der Waals interaction
4.Purine nitrogenous bases include
a. Adenosine & Thymine
b. Adenosine & Guanine
c.
d.
Cytosine & Thymine
Guanine & Uracil
c.
d.
Is hydrophobic
Can interact with other molecules
5.This figure represents a protein in its:
a. Secondary alpha helix structure
b. Secondary beta pleated sheet structure
c. Tertiary structure
d. Quaternary structure
6.This figure represents a protein in its:
a. Secondary alpha helix structure
b. Secondary beta pleated sheet structure
c. Tertiary structure
d. Quaternary structure
7.A molecule made of carbon and hydrogen atoms:
a. Is hydrophilic
b. Is polar
8.A hydrophobic molecule, in which a hydrogen is replaced by a hydroxyl group will:
a. Remain hydrophobic
c. Dissolve in water
b. Become hydrophilic
d. b and c are correct
9.The following molecules are an example of:
a.
b.
Geometrical isomers
Enantiomers
10.Phospholipid molecules:
a. Are structural lipids
b. Are amphipathic
c.
d.
Structural isomers
None of the above
c. Have glycerol backbone
d. All of the above are correct
11.An amino acid
a. Has a carboxyl group, weakly acidic
b. Has an amine group, weakly basic
c. Has a side chain that determine its chemical property
d. All of the above are correct
12.A tertiary structure of a protein includes:
a. Disulfide bridge
b. Hydrophobic bonds
c. Ionic bonds
d. All of the above
Chapter 4
13.Which of the following statements is CORRECT about prokaryotes and eukaryotes?
a. Both prokaryotes and eukaryotes have a nuclear membrane
b. Prokaryotes have a nucleus, while eukaryotes have a nucleoid
c. Prokaryotic cells are ten times larger than a eukaryotic cell
d. Prokaryotes do not have organelles, while eukaryotes have organelles
14.The nuclear lamina is a (an):
a. inner lining to support nuclear membrane
b. openings in the nuclear membrane
c. concentric membranes that separates the nucleus from the cytoplasm
d. important organelle in the cell
15.Nucleoli are:
a. Responsible for detoxification in cells
b. Found in the cytosol
c. the site of rRNA synthesis for
ribosomes
d. All of the above
16.Ribosomes synthesize:
a. Nucleic acids
b. Proteins
c.
d.
17.Smooth Endoplasmic Reticulum (SER):
a. Synthesize and modify proteins
b. Store calcium ions
c. Serve as a detoxification site
d. b & c
18._________ are small sacs of digestive enzymes.
a. Peroxisomes
b. Lysosomes
c.
d.
Lipids
Phospholipids
Endosomes
None of the above
19.The programmed cell death is called_________ and the involved enzymes are_____
a. necrosis; catalase
c. apoptosis; caspases
b. oxidative burst; cytochrome C
d. phagocytosis; hydrolases
20.What role(s) does the cytoskeleton play in a living cell?
a. maintaining the cell shape
c. contraction
b. movement
d. all of the above
21.The endoplasmic reticulum is continuous with the:
a. plasma membrane
b. inner nuclear membrane
c.
d.
outer nuclear membrane
inner lamina
22.The nucleus and mitochondria share which of the following features?
a. membrane pores
c. a double membrane
b. an inner folded membrane
d. conversion of energy
23.Which of the following describe the organelles and/or structure that plant cells have but animal cells
do not have?
a. nucleus, cell wall, lysosomes
b. glyoxysomes, Golgi complex, chloroplasts
c. cell wall, thylakoids, centrioles
d. chloroplasts, cell wall, large central vacuole
24.Enzymes present in the SER:
a. synthesize lipids
b. may be used for detoxification
c. synthesize carbohydrates
d. all of the above
25.Which cells have a plasma membrane, cytoplasm, ribosomes and DNA?
a. only animal cells
c. only eukaryotic cells
b. only prokaryotic cells
d. all cells
Chapters 5 and 6
26. Substances move through biological membranes against concentration gradients via
a. simple osmosis.
b. active transport.
c. reverse osmosis.
d. simple diffusion.
e. None of the above
27.In biological membranes, the phospholipids are arranged in a
a. bilayer, with the fatty acids pointing toward each other.
b. bilayer, with the fatty acids facing outward.
c. single layer, with the fatty acids facing the interior of the cell.
d. single layer, with the phosphorus-containing region facing the interior of the cell.
e. bilayer, with the phosphorus groups in the interior of the membrane.
28.A protein that forms an ion channel through a membrane is most likely to be
a. a peripheral protein.
b. an integral protein.
c. a phospholipid.
d. an enzyme.
e. entirely outside the phospholipid bilayer.
29.Cholesterol molecules act to
a. help hold membranes together.
b. transport ions across membranes.
c. attach to carbohydrates.
d. disrupt membrane function.
e. alter the fluidity of the membrane.
30.When placed in a hypertonic solution, plant cells
a. shrink.
b. swell.
c. burst.
d. transport water in.
e. concentrate.
31.
a.
b.
c.
d.
A transporter that moves one type of particle in one direction is _______.
uniporter
symporter
antiporter
pinocytosis
32. Cell signaling includes:
a.
Reception of signaling molecules
b.
Signal transduction
c.
d.
Response
All of the above
33. Up-regulation of the reception in the cell signaling means:
a.
more receptors are produced
c.
more target cells are needed
b.
receptors are degraded
d.
more signal molecules are needed
34. Hydrophobic signaling molecules like steroid hormones and vitamins
a.pass through the plasma membrane and bind to intracellular receptors
b.are released by neuron cells
c.binds directly to DNA
d.all of the above
35. IP3 binds to------- and DAG binds to----a.
ER / protein kinase C
b.
G protein / kinase
c.
phosphatase / kinase
d.
nucleus / plasma membrane
Subjective questions
Question-1
1. Name the structure that synthesizes proteins? Ribosome
2. Once polypeptides are synthesized, they are inserted to the lumen of which organelle?
Rough Endoplasmic Reticulum
3. How are glycoproteins transported from the RER to the Golgi complex?
Through vesicles that bud from RER and fuse with the cis Golgi complex
4. What is the difference between proteins and glycoproteins?
Proteins are not modified, while glycoproteins are modified with a sugar
5. What is the main function(s) of the Golgi complex? Processes, sorts, and modifies
proteins.
Question-2
Below is the representation of the general process of breaking down a dimer
➢ What is the name of this reaction? Hydrolysis reaction
➢ Add the missing element(s) ON the figure, to make the reaction complete (H2O,
enzyme)
➢ Indicate by an arrow ON the figure the linkage between the 2 units forming the dimer
➢ If these 2 units are two glucose molecules, what is the name of that linkage?
Glycosidic linkage
➢ If these 2 units are two amino acids, what is the name of that linkage? Peptide bond
➢ Circle the parts of the monomers that were involved in the dimer formation.
Question-3:
Please consider the following questions related to osmosis
Intravenous solutions (IV Fluids) must be prepared so that they are isotonic to red blood cells. A
0.9 % salt solution is isotonic to red blood cells.
a. Explain what will happen to a red blood cell if placed in a solution of 99.3% water and 0.7%
salt? Since this is a hypotonic solution (lower amount of dissolved substances=higher
amount of water), water will flow into the cell. It will get larger and / or burst
b. Explain what would happen to a red blood cell if placed in a solution of 90% water and 10%
salt? Since this is a hypertonic solution, water will flow out of the cell, and the cell will
lose mass and shrink
Question-4:
Consider the cell membrane in the below Figure.
1) Identify the types of membrane proteins A, B, and C.
A and B are peripheral proteins. C is integral protein.
2) State whether protein A, B, or C could be Amphipathic, Hydrophilic or Hydrophobic.
A= Hydrophilic
B= Hydrophilic
C= Amphipathic
3) Consider the following components of cell membrane. State for each if it is embedded in the
membrane or is on the surface of the membrane or could be in both locations.
Membrane proteins= embedded or on surface
Phospholipids= embedded
Carbohydrates= on the surface
4) For each of the following molecules state if they can pass freely by diffusion through the cell
membrane or can NOT.
CO2= Yes
Na+= No
H2O= Yes
Glucose= No
Ca2+= No
Amino acids= No