Molecular Cell Biology - Problem Drill 01: Introduction to Molecular Cell Biology Question No. 1 of 10 1. Which statement describes how an organism is organized from most simple to most complex? Question #1 (A) Chemical, tissue, cell, organ, system, organism. (B) Cell, chemical, tissue, organ, system, organism. (C) Tissue, cell, chemical, organ, organism, system. (D) Chemical, cell, tissue, organ, system, organism. Tissues are collections of cells and surrounding matrix. Cells are more complex than chemicals in the organism. Chemical is the most basic level of organization. D. Correct! The range is from chemical organization to organism. Remember the cells are made of chemicals, tissues are made of cells, organs are made of tissues, systems are coordinated organs, and an organism is made of systems.
Question No. 2 of 10 2. The four major classes of macromolecules are. Question #2 (A) Proteins, sugars, lipids, and carbohydrates. (B) Amino acids, sugars, carbohydrates, and proteins. (C) Proteins, carbohydrates, nucleic acid, and lipids. (D) Amino acids, carbohydrates, fats, and nucleic acids. Sugars are part of carbohydrates, and are not their own macromolecular category. Amino acids are part of peptides that make up proteins. C. Correct! These are the four groups of macromolecules. Fats are not their own class of macromolecules. Understand that macromolecules are composed of small components like sugars, fats, amino acids etc. and the four major macromolecules classifications PLay- NiCe : Proteins, Lipids, Nucleic acids, and Carbohydrates.
Question No. 3 of 10 3. Which of the following statements about DNA is False? Question #3 (A) It is composed of nucleic acids with a deoxyribose backbone. (B) It is a double stranded alpha helix structure. (C) Its nucleic acid bases pair according to the Watson-Crick principle. (D) There are eight different bases. This is true. DNA is a double stranded alpha helix. Nucleotides do pair up according to the Watson-Crick principle. D. Correct! There are only four bases that make up DNA. DNA is a fundamental molecule that has special attributes which make it unique. Some of these attributes, like its shape, molecular make-up are outlined here.
Question No. 4 of 10 4. Proteins are composed of which of these monomers? Question #4 (A) Glucose (B) Amino acids (C) Fatty acids (D) Nucleotides Glucose is a carbohydrate monomer. B. Correct! Amino acids are the building blocks of proteins. Fatty acids are a component of lipids and fats, not proteins. Nucleotide polymers for nucleic acids. You should recall that all macromolecules are made from smaller building blocks, or monomers. Proteins and peptides are made from amino acids.
Question No. 5 of 10 5. Which of these processes involves an RNA template instead of DNA? Question #5 (A) Transcription (B) Repair (C) Recombination (D) Translation Transcription is the copying of DNA into an RNA transcript. Repair occurs at the DNA level. Recombination, also takes place at the DNA level. D. Correct! Translation is the formation of peptide chains from an RNA transcript. Remember, DNA is the permanent template and RNA is the go between on the way to protein production.
Question No. 6 of 10 6. The combination of three consecutive bases which encode an amino acid is called. Question #6 (A) Codon (B) Triplet (C) Anticodon (D) Peptide A. Correct! A codon is a three base sequence that corresponds to an amino acid. A codon is a triplet of bases. The anticodon is the triplet of bases on a trna that binds to the codon. A peptide is a chain of amino acids. Review the progression from DNA to protein; DNA to RNA to protein. Codons first, then anticodons, and amino acids.
Question No. 7 of 10 7. The complete set of DNA structural elements and regulator proteins in a prokaryotic cell is called. Question #7 (A) A nucleus (B) The chromatin (C) An operon (D) A nucleolus Only eukaryotic cells have a nucleus. Chromatin refers to DNA and it associated regulatory proteins. C. Correct! Operon is right one. A nucleolus is a sub-compartment of the nucleus found in eukaryotic cells. Think about the structure of a prokaryotic cell. They are well known for the lack of nucleus, and have DNA in the cytoplasm.
Question No. 8 of 10 8. Which of the following are not types of eukaryotic gene regulators? Question #8 (A) Enhancers (B) Repressors (C) Inhibitors (D) Promoters Enhancers are involved in eukaryotic gene expression. Repressors are also involved in eukaryotic gene expression. C. Correct! Inhibitors are not a type of eukaryotic gene expression modulator. Promoters are the areas of DNA where repressors and enhancers exert their effects. Review the types of modulators which are involved in eukaryotic gene expression. Proteins bind the DNA upstream of gene encoding sequences in areas called promoters. Enhancers and repressors are both classes of such modulators.
Question No. 9 of 10 9. Which of the following is not a type of intracellular membrane transport? Question #9 (A) Simple diffusion (B) Facilitated diffusion (C) Active transport (D) Complex diffusion Passive transport down with rate determined by a molecules permeability, size, and concentration gradient. Carrier protein mediated but does not use energy. Uses both carrier proteins and metabolic energy, can move molecules against an electrochemical gradient. D. Correct! There is no such a term for intracellular membrane transport. Hence this is not the type of such. All the answers are types of membrane transport, except complex diffusion.
Question No. 10 of 10 10. The cytoskeletal elements that give shape to a cell and aids in movement do not include. Question #10 (A) Actin (B) Lipids (C) Microtubule (D) Intermediate Actin polymers are important for cellular locomotion and contraction of muscle cells. B. Correct! Lipids are not cytoskeletal elements. Made of tubulin polymers & are important for vesicle motility and separation of chromosomes during cell division. Are composed of proteins such as keratin and lamin & are important for cell adhesion and signaling. Cytoskeletal elements including actin, microtubules, and intermediate filaments make up the scaffold of the cell which gives and maintains shape and allows movements across substrates.