Smartbooks Chapter 2 Flashcards
The six most abundant elements in the human body are carbon, oxygen, hydrogen, phosphorus, calcium, and _____
nitrogen
_______ electrons are the electrons found in the outermost shell of the electron cloud.
Valence
Atoms of the same element that differ only in the number of neutrons are known as _____
isotopes
A cation has a net _____ charge.
positive
What is the term for an ion with a net negative charge (more electrons than protons)? Cation Isotope Electron Anion
Anion
Choose the six most abundant (by weight) elements that account for 98.5% of the body weight.
Carbon, oxygen, hydrogen, phosphorus, calcium, and nitrogen
What term refers to a covalent bond in which the electrons are not equally shared?
Polar
If an atom has 2 electrons in its innermost shell and 3 electrons in its outmost shell, how many valence electrons does it have?
3
Salt on a watermelon is an example of a ______.
mixture
Deuterium and tritium are isotopes of hydrogen. What is different about them?
They have a different number of neutrons
What term can be used to describe any molecule that is non-polar and does not dissolve in water?
Hydrophobic
What type of ion has lost an electron and, consequently, has a net positive charge?
Cation
Which term refers to polar molecules that dissolve in water?
Hydrophilic
The chlorine atom gains electrons to become a chloride ______.
anion
Saltwater is a solution of NaCl dissolved in water. In this example, NaCl is the solute and water is the ____
solvent
In a carbon dioxide molecule, electrons are shared equally among the atoms. What type of bond do they form?
Nonpolar covalent
In a solution, the solute can be a ______.
gas, solid, or liquid
A(n) ______ consists of substances that are physically blended but not chemically bound.
mixture
The abbreviation _____ is a measurement of acidity derived from the concentration of H+.
pH
Name a hydrophobic substance
Fats
Solution A prevents solution C from changing its pH. Solution A is therefore a what?
Buffer
Hydrophilic substances are soluble in ____
water
Energy contained in an object due to its position or state is referred to as what type of energy?
Potential
In a solution, the more abundant substance that dissolves another substance is known as what?
Solvent
The energy of motion is what type of energy?
Kinetic
The particles of matter that are dissolved in a solution are known as what?
Solute
Which of the following best describes what occurs in a decomposition reaction?
A molecule is broken down into smaller parts.
pH is a measurement of the concentration of what?
Hydrogen ions
Two amino acids are brought together to form a dipeptide. Which type of reaction is this?
Synthesis
Substances that resist changes in pH are known as _____
buffers
True or false: Some catalysts speed up reactions, while other catalysts slow down reactions.
False
Which term refers to energy in a system that is not being used to do work?
Potential energy
The term ______ refers to the sum of all the chemical reactions in the body.
metabolism
______ energy is energy that is actively doing work.
Kinetic
Which of the following describes a catabolic reaction?
Large protein molecules are broken down into smaller amino acids during digestion.
Reason: Catabolic reactions are decomposition reactions. Larger molecules are broken down into smaller molecules, and energy is released.
A chemical reaction in which a larger molecule is broken down into smaller ones is which type of reaction?
Decomposition
The term anabolism specifically applies to metabolic reactions that do which of the following?
Build large molecules from small molecules
A chemical reaction in which two or more smaller molecules combine to form a larger molecule is what type of reaction?
Synthesis
In many biochemical reactions, individual subunits are joined to form larger macromolecules with the release of water molecules. How are these reactions classified?
Dehydration synthesis reactions
How do catalysts affect reaction rates?
They increase reaction rates.
Name the chemical reaction that breaks a covalent bond in a molecule by adding an OH group to one side of the bond and H to the other side, thus consuming a water molecule.
Hydrolysis
Which 3 things are true regarding metabolism?
1) It can be defined as the sum of all of the chemical reactions in the body.
2) It includes reactions where new molecules are synthesized.
3) It includes reactions where molecules are broken down.
Which term is used to refer to a simple sugar, or sugar monomer?
Monosaccharide
Which term applies to metabolic decomposition reactions that release energy?
Catabolism
Name 5 types of lipids
- Steroids
- Fatty acids
- Phospholipids
- Eicosanoids
- Triglycerides
Metabolic reactions that use energy and build more complex molecules from less complex molecules are considered which type of reaction?
Anabolic
A(n) ______ is a lipid that consists of two hydrophobic fatty acid tails and a hydrophilic phosphate head.
phospholipid
Sucrose or table sugar is formed when the simple sugars fructose and glucose are covalently bonded. This reaction releases water. What is the name of this type of reaction?
Dehydration synthesis
Which of the following best describes the chemical reaction called hydrolysis?
A. A covalent bond is broken by adding an OH to one side of the molecule, and an H to the other side.
B. Two ions join together to form a salt.
C. Electrons are transferred between two molecules.
D. A water molecule is removed from a molecule when it creates a covalent bond.
A. A covalent bond is broken by adding an OH to one side of the molecule, and an H to the other side.
Disaccharides can be broken down into ______.
monosaccharides
Peptide bonds are used to join two of these together.
Amino acids
Hydrophobic organic molecules, such as fatty acids, fats, steroids, and prostaglandins, are classified as what type of molecule?
Lipids
Which of the following molecules are the major component of the plasma membrane?: Phospholipids Steroids Prostaglandins Glycoproteins
Phospholipids
In many biochemical reactions, individual subunits are joined to form larger macromolecules with the release of water molecules. How are these reactions classified?
Dehydration synthesis reactions
The ____ structure of a protein is its amino acid sequence.
Primary
Name the chemical reaction that breaks a covalent bond in a molecule by adding an OH group to one side of the bond and H to the other side, thus consuming a water molecule.
Hydrolysis
Name the type of bond that holds amino acids together in a protein molecule.
Peptide bond
The ____ level of protein structure is determined by the folding of the protein due to hydrogen bonding between amino acids to form alpha helices and beta-pleated sheets.
secondary
Choose the lipids in the list below: Eicosanoids Steroids Phospholipids Polysaccharides Polypeptides Fatty acids Triglycerides
Eicosanoids Steroids Phospholipids Fatty acids Triglycerides
A(n) _____ is a lipid that consists of two hydrophobic fatty acid tails and a hydrophilic phosphate head.
phospholipid
Which level of protein structure is due to bending and folding into various globular and fibrous shapes?
Tertiary
The quaternary structure consists of:
the interaction between multiple polypeptide subunits.
What does the quaternary structure of a protein depend upon?
Interactions between multiple polypeptide chains
Which of the following best describes the chemical reaction called hydrolysis?
A covalent bond is broken by adding an OH to one side of the molecule, and an H to the other side.
Which term refers to a change in the three-dimensional conformation of a protein that destroys its functional properties?
Denaturation
Name the level of protein structure that is determined by the folding of the protein into alpha helices and beta sheets due to hydrogen bonding between amino acids.
Secondary
A _____ is the substance that an enzyme acts upon.
substrate
Hydrophobic organic molecules, such as fatty acids, fats, steroids, and prostaglandins, are classified as what type of molecule?
Lipids
Which of the following is another term for enzyme?
Biological catalyst
The folding of proteins into various globular and fibrous shapes is referred to as the
____ structure of the proteins.
tertiary
Which term refers to the energy needed to get a chemical reaction started?
Activation energy
The _____ level of protein structure is determined by the interactions between two or more polypeptide chains within a protein.
quaternary
Which of the following statements about enzymes are true?:
Enzymes speed up reaction rates by lowering the activation energy of a specific reaction.
Enzymes show enzyme-substrate specificity.
Enzymes may act as reactants in the reactions they catalyze.
Enzymes are not affected by pH.
Enzymes are not consumed in the reactions they catalyze.
Enzymes speed up reaction rates by lowering the activation energy of a specific reaction.
Enzymes show enzyme-substrate specificity.
Enzymes are not consumed in the reactions they catalyze.
Which of the following best describes denaturation?
The unfolding of a protein’s three-dimensional shape
Which term refers to the substance upon which an enzyme acts?
Substrate
Indicate how pH and temperature affect the activity of an enzyme:
Altering the enzyme concentration
Altering the shape of the substrate binding site
Altering the substrate concentration
Causing a conformational change in the enzyme
Altering the shape of the substrate binding site
Causing a conformational change in the enzyme
A(n) _____ is a protein that functions as a biological catalyst.
enzyme
Which is an example of a nucleotide?
ATP
What effect do enzymes have on the activation energy of a chemical reaction in the body?
Enzymes lower activation energy
True or false: An enzyme is consumed by the reaction it catalyzes.
False
Which term refers to a change in the three-dimensional conformation of a protein that destroys its functional properties?
Denaturation
Which of the following factors affect enzyme conformation?:
Temperature
Enzyme concentration
pH
Temperature & pH
Which organic molecules are composed of a nitrogenous base, a monosaccharide, and a phosphate group?
Nucleotides
Nucleotides contain a phosphate, a sugar and a nitrogenous _____
base
Which is an example of a nucleotide?
ATP
