,
,
,
,Chapter 1 Biochemistry and the Unity of Life 3
12. After hydrogen and oxygen, the next most common element in living
systems is .
13. A chemical that can dissolve in water is said to be .
14. A nucleotide consists of one or more groups, a 5-carbon ribose
sugar, and a nitrogen-containing aromatic ring group.
15. The most common carbohydrate fuel is .
16. Heritable information is packaged into discrete units called .
17. A group of enzymes called catalyze replication.
18. Although all cells in an organism have the same DNA, tissues differ
due to selective .
19. The basic unit of life is considered the .
20. Secretory vesicles fuse with the plasma membrane to release material
outside of the cell via .
Multiple-Choice Questions
21. The structure of DNA described by Watson and Crick
In higher organisms, which of the following is compos ed of a polymer
22.included:
A) a double
with helix.
double-stranded phosphodiester-linked monomers?
B)
A)the
RNAsugar–phosphate backbone aligned in the
center
B) DNAof the helix.
C)
C)the base pairs that are stacked on the inside of the
protein
double helix.
D) carbohydrate
D) A and B.
E) A and C.
,Chapter 1 Biochemistry and the Unity of Life 4
E) None of the above.
23. What gives proteins such a dominant role in biochemistry?
A) the variation in protein sizes
B) the ability to act as a blueprint
C) their ability to self-replicate
D) their ability to spontaneously fold into complex three-dimensional
structures
E) All of the above.
24. Proteins are chiefly composed of which of the following?
A) carbohydrate and amino acids
B) long unbranched amino acid polymers
C) peptide bonds formed between lipid moieties
D) aggregated amino acids
E) A and B
Section 1.3
25. How a protein folds is determined by:
A) whether the environment is hydrophobic or hydrophilic.
B) the location in the cell in which the protein is located.
C) the pH of the cytoplasm.
D) the order of the amino acids found in the sequence.
E) All of the above.
,Chapter 1 Biochemistry and the Unity of Life 5
26. The half-life of which of the following is likely to be shortest?
A) protein
B) lipid
C) carbohydrate
D) DNA
E) RNA
27. The central dogma describes:
A) the formation of cells from individual components.
B) the selective expression of genes.
C) the flow of information between DNA, RNA, and protein.
D) the work of polymerases on RNA and DNA.
E) All of the above.
28. Translation takes place on/in the:
A) ribosomes.
B) smooth endoplasmic reticulum.
C) nucleus.
D) DNA polymerases.
E) DNA parent strand.
29. Which of the following organelles has a double membrane?
A) nucleus
B) endoplasmic reticulum
C) mitochondria
D) plasma membrane
E) A and C
F) All of the above.
,Chapter 1 Biochemistry and the Unity of Life 6
30. The main function of the plasma membrane is to:
A) provide the interior of the cell an enclosed environment that no
molecules may cross.
B) provide a selectively permeable barrier with the aid of transport
proteins.
C) give eukaryote and prokaryote cells structural strength.
D) allow only the free passage of water in and out of the cell.
E) None of the above.
31. Filaments and microtubules are components of a network called the:
A) chloroplast.
B) cytoplasm.
C) cytoskeleton.
D) cell wall.
E) B and D.
32. Poisons that kill an organism as a result of a loss of high-energy ATP
molecules are most likely to target which organelle?
A) mitochondria
B) cytoskeleton
C) cytoplasm
D) endoplasmic reticulum
E) nucleus
33. A secreted protein would be processed through organelles in the
following order:
A) nucleus; secretory vesicle; Golgi complex.
B) cytoplasm; Golgi complex; cytosol; secretory vesicle.
C) endoplasmic reticulum; cytoplasmic reticulum; Golgi complex.
D) nucleus; cytoplasm; endoplasmic reticulum; Golgi complex;
secretory vesicle.
E) None of the above.
34. Extracellular material is taken into the cell via which process?
A) exocytosis
B) phagocytosis
, Chapter 1 Biochemistry and the Unity of Life 7
C) lysosome-mediated endocytosis
D) reverse secretory mechanism
E) phago-cytosolic internalization
35. The rigid material that provides structural support to a plant cell is/are
called the:
A) plant cytoskeleton.
B) plasma membrane.
C) cell wall.
D) chloroplast anchor proteins.
E) microfilaments and microtubules.
36. In studying secreted proteins, you find that Substance X inhibits the secretion
of a labeled protein. However, you do find a fully synthesized, folded, and
glycosylated proteins in the cell. Where is the most likely site in the synthesis and
secretion of proteins for Substance X to act?
A) nucleus during translation
B) budding of the secretory granule
C) translation on the ribosome
D) enzyme modification in the Golgi
E) All of the above.
37. Below is the scheme known as the central dogma. Each of the arrows (A, B, C)
represents a particular process in gene expression. A, B, and C, respectively, are:
A) replication, transcription, translation.
B) reverse transcription, transcription, translation.
C) transcription, translation, replication.
D) replication translation, expression.
E) None of the above.