BIO 121 Montgomery County Community College Final Exam 2025

In 6C6H12O6 there are ________ oxygen atoms? - Correct Ans-36 The molecular mass of Na2CO3 is... - Correct Ans-106 In the equation 2H2 + 02 --- 2H2O.... A. H2, O2, and H2O are all compounds B. H2, O2, and H2O are all elements C. Only H2 and O2 are compounds D. Only H2O is a compound - Correct Ans-D. Only H2O is a compound The tendency of water molecules to stick with another molecule other than water is.... - Correct Ans-Adhesion Which is less dense, solid water or liquid water? - Correct Ans-Liquid water-the molecules can fit closer together because they are breaking and reforming, unlike ice molecules pH of 3 is how many times more acidic than pH of 6? - Correct Ans-1000x more Covalent Bonds - Correct Ans-share electrons Ionic Bonds - Correct Ans-accept electrons What does the body NOT break down for energy? - Correct Ans-RNA 3 most common atoms in our body - Correct Ans-hydrogen, oxygen, and carbon Which of the following contains a carboxyl group and an amino group? A. Amino acid B. Fat C. Sugar D. Vinegar - Correct Ans-A. Amino acid Which of the following statements about dehydration synthesis (condensation) is FALSE? A. One monomer loses hydrogen atoms, other hydroxyl group B. H2O is formed as the monomers are joined C. Covalent bonds are formed between monomers BIO 121 BIO 121 D. Animal digestive systems utilize to break down food - Correct Ans-D. Animal digestive systems utilize to break down food An oil may be converted into a substance that is solid at room temperature by - Correct Ans-adding hydrogen, decreasing the number of double bonds in molecules Fatty acids with double bonds between some of their carbons are said to be - Correct Ans-unsaturated Primary structure of a protein is - Correct Ans-the amino acid sequence of the polypeptide chain Which of the following are false about nucleotides? A. Nucleotides contain lipids B. Nucleotides contain sugar molecules C. Nucleotides can be linked together to form nucleic acids D. Nucleotides contain nitrogenous bases - Correct Ans-A. Nucleotides contain lipids A molecule with the formula C18H32O16 is a - Correct Ans-polypeptide Monosaccharides ratio - Correct Ans-1:2:1 Ex. Glucose C6H12O2 Isomers are - Correct Ans-molecules that have the same molecular formula Disaccharide are - Correct Ans-2 monosaccharides together with condensation reaction (H2O is taken out) Hydrolysis reaction is - Correct Ans-adding water Polysaccharides are - Correct Ans-Disaccharides + monosaccharides also hydrophilic Nucleoid region of prokaryotic cell - Correct Ans-contains the cells of DNA Function of nucleoulus is... - Correct Ans-to manufacture ribosomal RNA Which location in the cell is UNLIKELY to contain ribosomes or ribosomal units? - Correct Ans-Plasma membrane Order in which insulin passes through from its production to its exit from the cell - Correct Ans-Rough ER, transport vesicles, golgi apparatus, transport vesicles, cell membrane Gap Junctions - Correct Ans-connect cytoplasm of 2 cells and allows molecules, ions, and electric impulses BIO 121 BIO 121 Tight Juntctions - Correct Ans-Prevents cell leakage Anchoring Junctions - Correct Ans-Proteins fasten cells together What part of the cell is responsible for ATP? - Correct Ans-Mitochondria What part of the cell is responsible for lipids and proteins? - Correct Ans-ER Thermodynamics First Law - Correct Ans-Energy can be transformed and transferred, but cannot be destroyed or created. Thermodynamics Second Law - Correct Ans-In each energy transformation, some energy is lost in the form of heat When a cell uses chemical energy to perform work, it uses the energy released from a(n) ________ reaction to drive a(n) ________ reaction. - Correct Ans-exergonic, endergonic When an enzyme catalyzes a reaction... - Correct Ans-it lowers the activation energy of the reaction Substrates bind to an enzyme's ______ site. - Correct Ans-Active Heating inactivates enzymes by - Correct Ans-changing the enzyme's three-dimensional shape by breaking peptide bonds Which of the following processes is endergonic? A. Burning of wood B. Breakdown of glucose C. The synthesis of glucose form carbon dioxide to water D. Cellular Respiration - Correct Ans-C. the synthesis of glucose from carbon dioxide and water Catalysts - Correct Ans-Speed up/start chemical reactions and lower the activation level Enzyme Competitive Inhibition - Correct Ans-Competing for one active site Non-competitive inhibition - Correct Ans-Two sites that fit perfect (allosteric site) Feedback Inhibition - Correct Ans-Substrate becomes product to feedback into enzyme to change shape Solute - Correct Ans-subject being dissolved Solute - Correct Ans-subject doing the dissolving BIO 121 BIO 121 Passive transport - Correct Ans-No energy required Facilitated Diffusion - Correct Ans-Needs help (charged ions or big molecules) Osmosis - Correct Ans-Only allows water Isotonic - Correct Ans-cell volume will not change Hypertonic - Correct Ans-cell will shrink (higher water level) Hypotonic - Correct Ans-Cell will expand (lower water level) Active transport - Correct Ans-requires ATP and transport proteins (low to high concentration) Bulk transport - Correct Ans-too much to move through the membrane Phagocytosis - Correct Ans-bringing in a cell (food) Pinocytosis - Correct Ans-bringing in liquid Receptor-mediated endocytosis - Correct Ans-bringing in specific lipids Which of the following would have the most trouble crossing a biological membrane by diffusing through lipid bilayer? A. O2 B. CO2 C. Na+ D. a small, nonpolar molecule - Correct Ans-Na+ (charged ion) Diffusion does not require the cell to expand ATP. Therefore, diffusion is - Correct Ans Passive transport You are adrift in the Atlantic Ocean, and, being thirsty, drink the surrounding seawater. As a result, - Correct Ans-You dehydrate yourself Facilitated diffusion across a biological membrane requires ___________ and moves a substance ________ its concentration gradient. - Correct Ans-transport proteins, down The carrier molecules used in active transport - Correct Ans-Proteins Autotrophs - Correct Ans-Producers