Untitled Flashcards Set

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LBM Exam Review

1.     Polysaccharides can be broken down into which specific monosaccharide?

Polysaccharides can break down into glucose, fructose, and galactose.

2.     If a carbohydrate molecule contains 32 hydrogen atoms, how many carbon atoms does it contain?

32 hydrogen atoms = 16 carbon atoms

1:2 ratio

3.     Starch and cellulose are both polysaccharides found in plants.  How is the function of each different?

Starch: storage made up of glucose

Cellulose: component of tough cell wall

4.     Why do humans not consume cellulose to obtain energy?

They don’t all have the same enzyme linkages and enzymes to break it down. That enzyme would be cellulase.

5.     Would you rather consume a meal of celery or potatoes the night before a marathon?  Defend your answer, being sure to include what you know about the different types of carbohydrates in your response.

Potatoes contain a high percentage of starch, which can be used for energy.

6.     Name the 3 parts of a nucleotide.

Nitrogenous base, pentose sugar, and phosphate group.

7.     What role does the base sequence of a series of bonded nucleotides provide for an organism?

It provides them with DNA and RNA to pronounce specific genes.

8.     Explain how RNA and DNA work like a tag team in the cell in order to complete the task of storing and expressing genetic information.

DNA – provides directions for replication in each cell

RNA – messenger and is transcribed from DNA; translation also occurs

9.     If adenine always pairs with thymine (or uracil) and cytosine always pairs with guanine, construct a general statement involving purines and pyrimidines to describe base pairing rules in DNA.

In DNA, Adenine always pairs with Thymine. If a pattern reads ATTCG, the connecting paris would be TAAGC, Uracil would not be used since it is only for RNA.

10.  Explain why DNA needs the presence of RNA for it to be a functional molecule.

DNA needs RNA to be functional because RNA acts as a carier for genetic information from DNA to the ribosomes for synthesis.

11.  Suppose you discover a new type of virus.  Your research indicates that the molecular chemistry of the virus includes the nitrogen base uracil, but not thymine.  Which nucleic acid does your research support is utilized by this virus?  Why did you come to this conclusion?

Ribonucleic acid (RNA). This is because RNA uses Uracil, and DNA uses thymine.

12.  Briefly explain why proteins, carbohydrates, and nucleic acids are considered biomolecular polymers.

They are considered biomolecular polymers because they are large molecules built from smaller, repeat units called monomers linked together by covalent bonds.

13.  Which of the three components of an amino acid is most comparable in functionality to the nitrogen base of a nucleotide?

The R-group. The nitrogen base of a nucleotide is what distinguishes it from other nucleotidesm sane as an R-group for an amino acid.

14.  Amino acids each have an H atom on one and an OH group on the other end.  What type of reaction do you think could be used to effectively join two amino acids together?  What is the product of this reaction?

Two amino acids can be joined through a dehydration synthesis (or condensation) reaction, where a water molecule is removed, forming a peptide bond and a dipeptide. The type of reaction involves the removal of a water molecule (H20) to form a new bond.

15.  Of the three major components of each amino acid (Carboxyl Group, Amine, R Group Side Chain), which would you use to distinguish between two different amino acids?  Why would you choose this particular component?

R-group. The nitrogen base of a nucleotide is what distinguishes it from other nucleotides, same as an R-group for an amino acid.

16.  Suppose you took two amino acids, valine and tyrosine, and switched their R-group side chain components.  Would this change the identity and function of the amino acids?  Why or why not?

Yes, the identity would change because the identity of an amino acid is determined by the R chain side group. The function would likely change especially if the R chain side group where very chemically different. Example: sickle cell anemia

17.  What is the correct hierarchy of protein structure levels?

Primary; Secondary; Tertiary; Quaternary.

18.  Briefly explain the importance of having the accurate primary structure for appropriate protein function.

The accurate primary structure (amino acid sequence) is crucial for proper protein function because it dictates the protein’s 3D shape, which in turn determines its interactions and biological activity.

19.  The alpha helix shape and pleated sheet formation refer to which level of protein organizational structure?

The alpha helix and pleated sheet refer to the Secondary Structure.

20.  What are two ways in which you could denature a protein?

Two common ways are exposing it to extremely high temperatures or vast changes in pH.

21.  Pick two classes of proteins and match them with their specific function.

Structural Proteins: Support; Silk fibers (cocoons)

Storage Proteins: Storage of amino acids; Ovalbumin (egg white)

22.  How do amino acids vary in their properties?

Amino acids vary in their properties due to the differences in their side chains (R-groups). Those groups determine their chemical nature, including polarity, charge, and reactivity.

23.  Why is it significant that cell membranes are composed of amphiphilic (phospholipid bilayers) molecules?

It allows them to form a bilayer structure, creating a selectively permeable barrier that can separate the cell’s interior from the external environment.

24.  If a lipid is a liquid at room temperature, it is a good assumption that this lipid does/does not contain double bonds.  Explain your answer.

If it is at room temperature, it is a good assumption that this lipid does contain double bonds, as these bonds create kinks that prevent tight packing and lead to a liquid state.