The Chemistry of Life Review

Which of these statements does NOT describes how organisms could use molecules of glucose?

• Several glucose molecules could be assembled into a larger molecule

• Glucose molecules could be broken apart to form smaller molecules

• The atoms of glucose molecules could be combined with other elements to form a different molecule

• Glucose molecules can be combined together to create DNA

What structural feature does glucose share with larger organic molecules, including DNA and proteins?

• A basic structure, or backbone, formed by chains of carbon atoms

• A ratio of 1 carbon atom to 2 hydrogen atoms to 1 oxygen atom

• The presence of double covalent bonds

• Strong bonds between carbon atoms that cannot be broken

Todd is comparing a model of a sugar molecule to a model of an amino acid. Which of the following evidence statements would be supported by the two models?

• Sugars and amino acids are made of exactly the same elements

• Sugars and amino acids have the same structure

• Sugars and amino acids are made of the same elements except sugars also contain phosphorus

• Sugars and amino acids are made of the same elements except amino acids also contain nitrogen

What is the best definition of "atom"?

• pure substance that consists entirely of one type of atom

• the basic unit of matter

• smallest unit of most compounds that has all the properties of that compound

• negatively charged particle

What is the best definition of "covalent bond"?

• atom that has a positive or negative charge

• chemical bond formed when one or more electrons are transferred from one atom to another

• slight attraction that develops between oppositely charged regions of nearby molecules

• type of bond between atoms in which the electrons are shared

Paula is investigating a chemical reaction involving carbon compounds. Which of these results could NOT occur, according to scientific laws about chemical reactions, matter, and energy?

• The reaction releases energy to the environment

• The reaction absorbs energy from the environmnet

• The reaction occurs faster in the presence of a certain protein

• The mass of carbon in the products is greater than the mass of carbon in the reactants

What is the best definition of "molecule"?

• smallest unit of most compounds that displays all the properties of that compound

• pure substance that consists entirely of one type of atom

• atom that has a positive or negative charge

• the basic unit of matter

Two students are developing a computer simulation of a chemical reaction that forms amino acids. Their simulation uses colored spheres to represent atoms of different elements. It uses lines connecting the spheres to represent chemical bonds. For the simulation to be accurate, which of these features should be included?

• lines that break and reform between the spheres

• spheres that break apart into small pieces

• lines that never break once they are placed

• spheres that appear during the simulation of the reaction

What is the best definition of "hydrogen bond"?

• force of attraction between different kinds of molecules

• dissolving substance in a solution

• weak attraction between a hydrogen atom and another atom

• attraction between molecules of the same substance

What is the best definition of "electron"?

• negatively charged particle

• atom that has a positive or negative charge

• the basic unit of matter

• smallest unit of most compounds that displays all the properties of that compound