Download Weekly Assignment #1

Name:_________________________________
Due April 14, 2010
Chapter 3- KEY
1. Define the terms “monomer” and “polymer.” Connect these two terms by using them
in a complete sentence (.5pt).
Monomer- chemical subunit that serves as a building block of a polymer.
Polymer- large molecule consisting of many molecular subunits (monomers)
covalently joined together in a chain.
A polymer consists of multiple subunits called monomers.
2. List the four main types of macromolecules found in your body (.5pt).
Lipid, Proteins, Carbohydrates, Nucleic Acids
3. What are the monomers and polymers of three of the four types of macromolecules
(lipids are excluded)? Provide the broad name (as opposed to an example) for the
monomer and polymer of each macromolecule (1pt).
Lipids- no true monomer, but fatty acids and glycerol
Proteins-amino acids
Carbohydrates-Monosaccharide
Nucleic Acids-nucleotides
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4. Name the 6 functional groups of organic compounds and include their chemical
formula (.5pt).
Hydroxyl- OH
Carbonyl- C=O
Carboxyl- COOH
Amino- NH2
Phosphate OPO32Methyl CH3
5. What are the two “trademark” functional groups that make up a sugar? (.5pt)
Hydroxyl group and carbonyl group
6. Describe what an enzyme is. Include it is made of (i.e., proteins, carbohydrates, lipids
or nucleic acids) its function and how it influences chemical reactions in cells (1pts).
An enzyme is a protein that acts as a chemical catalyst that speeds up reactions in
cells.
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7. What type of reaction creates polymers? (.5pt)
Dehydration
8. How many water molecules are created when 6 monomers are combined into a
polymer? (.5pt)
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9. Hydrocarbons…….(.5pt)
A) are inorganic compounds.
B) are composed of carbon atoms that are attached to hydrogen skeletons.
C) contain only carbon and hydrogen atoms.
D) consist of atoms linked exclusively by single bonds.
E) All of the choices are correct.
10. Describe the difference between saturated and unsaturated fats (.5pt).
Saturated fats have the maximum number of H possible and no double bonds.
Unsaturated fats have less than the maximum number of H and include double
bonds
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11. Are the following molecules isomers? (.5pt)
A.
&
B.
C.
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12. Where in the body are phospholipids found and why are they suited for that purpose?
(.5pt)
Phospholipids are found in the cell membrane. Their hydrophilic and hydrophobic
properties of the molecule make it suitable for use in a membrane as they act to
form a barrier.
13. Name the 4 levels of structure in proteins and describe each level (1pts).
Primary- unique sequence of amino acids
Secondary- polypeptide folds and coils into an alpha helix or a pleated sheet
Tertiary- overall three-dimensional shape of the protein
Quaternary- protein subunits interact
14. What are the roles of DNA and RNA in a cell? What base pairs do they each use?
(1pt)
DNA contains the genetic information for inheritance. Base pairs are A,T,C,G
RNA works as an intermediary between DNA and protein synthesis. Base pairs are
A, U, C, G
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15. Explain how heat, pH and other environmental factors interfere with protein function
(.5pt).
Heat, pH and other environmental factors can cause a protein to denature, which is
when the shape of the protein is altered, affecting its function.
16. Describe the differences in bonding of lipids, proteins, and carbohydrates (.5pt).
Lipids consist mainly of C and H held via non-polar covalent bonds
Proteins consist of functional groups covalently bonded to a central C
Carbohydrates tend to bond in rings
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Ch 4
1. What is meant by a large surface area to volume ratio? How does this impact cells?
(1pt)
When something has a large surface area to volume ration it means that the object
has a large amount of surface area per unit of volume. For cells, this ratio impacts
how large they can be, transportation of nutrients and wastes in and out, and
diffusion distance inside the cell.
2. List the differences between Prokaryotic and Eukaryotic cells (.5pt)
Prokaryotic
Smaller
No nuclear
membrane
Eukaryotic
Larger
True nucleus, consisting
of nuclear membrane &
nucleoli
Membrane-enclosed
organelles
Cell wall
Absent
Present
Usually present;
chemically complex
When present, chemically
simple
Plasma membrane
Present
Present
Cytoplasm
Ribosomes
Chromosome (DNA)
arrangement
Present
Present
Single circular
chromosome; lacks
histones
No meiosis; transfer
of DNA fragments
through cell-to-cell
contact
Present
Present
Multiple linear
chromosomes with
histones
Involves meiosis
Size of cell
Nucleus
Sexual reproduction
3. How do DNA and chromosomes differ in Prokaryotic and Eukaryotic cells (.5pts)
Prokaryotic DNA is arranged in a circular “chromosome”.
Eukaryotic DNA is arranged in linear, true chromosomes
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4. Where else in a cell can DNA be found and how is it hypothesized that it got there?
(1pt)
Mitochondria and chloroplasts. Hypothesized that they were once independent
entities existing on their own, but through endosymbosis, they became part of the
greater cell as we know it today
5. Briefly describe the function of the following: (1pts)
a. Golgi Apparatus- works with the ER to “receive” and “ship” vesicles. Modifies
products from the ER
b. Ribosome- carry out protein synthesis. Are present in free and bound state.
c. Smooth Endoplasmic Reticulum- engages in cellular metabolism. Synthesize lipids,
steroids, oils and phospholipids. Also stores calcium ions.
d. Mitochondria- carry out cellular respiration, converting chemical energy to sugars
and ATP.
e. Lysosome- Digest things within the cell.
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6. How do fibers in the cytoskeleton differ from one another? (.5pt)
The cytoskeleton contains microfilament, intermediate filament and microtubule
fibers.
Microfilament fibers are rod-like fibers made of actin arranged in a double twisted
chain.
Intermediate filament fibers are made of various fibrous proteins and are ropelike
in structure
Microtubule fibers are straight, hollow tubes consisting of tubulins.
7. Explain the different roles that the three types of junctions perform and where they
may be found in the body (1pt).
The three types of junctions are Gap, Tight and Anchoring.
Gap junctions are channels that allow small molecules through protein lined pores
between neighboring cells.
Tight junctions occur when the membrane of neighboring cells are pressed tightly
together forming a tight seal that prevents any leakage.
Anchoring junctions fasten cells into sheets and anchor the sheets in the cytoplasm.
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8. What structures are found in plant cells, but not animal cells? (.5 pt)
Plants have a cell wall, vacuoles and chloroplasts
9.Label each organelle (1pt)
Rough
endoplasmic
reticulum
Smooth endoplasmic
reticulum
Nucleus
Flagellum
Lysosome
Centriole
Ribosomes
Golgi
apparatus
Peroxisome
Plasma membrane
Mitochondrion
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10. Explain how the hydrophobic properties of lipids create a membrane that is semipermeable (.5 pt).
The “head” is hydrophilic and the tail is hydrophobic. The hydrophilic head is
exposed to the water and the hydrophobic portion is protected inside the membrane.
This arrangement allows water and non-polar molecules to easily pass through the
hydrophobic interior of the membrane, but polar molecules must be assisted
through
11. Imaging you discovered a new type of cell unknown to science. What features would
you look for to determine if the cell was prokaryotic or eukaryotic? (.5 pt)
Membrane bound nucleus, DNA arrangement, the overall size of the cell, if the
organelles were bounded by membranes, and how the cell reproduced .
12. The cells that produce hair contain a lot of ________, while the cells that produce the
oils that coat the hair contain a lot of ________ (.5 pt).
A) smooth endoplasmic reticulum . . . lysosomes
B) rough endoplasmic reticulum . . . smooth endoplasmic reticulum
C) smooth endoplasmic reticulum . . . rough endoplasmic reticulum
D) microbodies . . . lysosomes
E) nuclei . . . chromatin
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13. A drug that interferes with microtubule formation is likely to completely disrupt
(.5pt)
A) the production of ribosomes.
B) the amoeboid motion of a cell.
C) the function of lysosomes.
D) contraction of muscle cells.
E) the movements of sperm cells.
14. A child dies following a series of chronic bacterial infections. At the autopsy, the
physicians are startled to see that the child's white blood cells are loaded with vacuoles
containing intact bacteria. Which of the following explanations could account for this
finding? (.5 pt)
A) A defect in the Golgi apparatus prevented the cells from processing and excreting the
bacteria.
B) A defect in the rough endoplasmic reticulum prevented the synthesis of the antibodies
(defensive proteins) that would have inactivated the bacteria.
C) A defect in the cell walls of the white blood cells permitted bacteria to enter the cells.
D) A defect in the lysosomes of the white blood cells prevented the cells from
destroying engulfed bacteria.
E) A defect in the surface receptors of the white blood cells permitted bacteria to enter
the cells.
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