Anatomy Ch. 2

What does a phospholipid have?

Both polar and nonpolar regions

What organic compound do brain cells primarily rely on for fuel?

Glucose

Explain the chemistry behind carbon's affinity for covalently bonding in organic compounds

Means that many distinct and relatively stable organic molecules nevertheless readily form larger, more complex molecules known as macromolecules

Nitrogen has an atomic number of seven. How many electron shells does it likely have?

Two

Discuss the role of buffers in helping the body maintain pH homeostasis

A buffer is a solution of a weak acid and its conjugate base A buffer can neutralize small amounts of acids or bases in body fluids

What makes an atom an isotope?

A different number of neutrons makes an atom of isotope

Describe the structure of proteins, and discuss their importance to human functioning

A protein is an organic molecule composed of amino acids linked by peptide bonds Proteins are components of many of the body's functional chemicals and build up many parts of the body

What is a functional group that is part of a building block of proteins?

Amino

Distinguish between acids and bases, and explain their role in pH

An acid is a substance that releases hydrogen ions (H+) in solution A base is a substance that releases hydroxyl ions (OH-) in solution, or one that accepts H+ already present in solution A solution's pH is the negative, base-10 logarithm of the hydrogen ion (H+) concentration of the solution

Distinguish between atomic number and mass number

An atomic number shows the number of protons in the nucleus of the atom, which identifies the element An element's mass number is the sum of the number of protons and neutrons in its nucleus

What is the difference between elements and compounds?

An element is an atom or molecule made of a single type of atom A compound is a molecule made of two or more different elements

Compare and contrast inorganic and organic compounds

An inorganic compound is a substance that does not contain both carbon and hydrogen An organic compound, then, is a substance that contains both carbon and hydrogen

When an atom donates an electron to another atom, what does it become?

An ion

How do ions, anions, and cations compare?

An ion is an atom that has an electrical charge A positively charged ion is known as a cation A negatively charged ion is known as an anion

What is the key difference between ionic and covalent bonds?

An ionic bond is an ongoing attraction between ions of opposite charge (metals and non-metals) Molecules formed by a covalent bond share electrons in a mutually stabilizing relationship (non-metals)

What is the smallest unit of an element that still retains the distinctive behavior of that element?

Atom

Identify four types of organic molecules essential to human functioning

Carbohydrates Lipids Proteins Nucleotides

Provide examples of three types of carbohydrates, and identify the primary functions of carbohydrates in the body

Carbohydrates are a critical fuel source Monosaccharides Disaccharides Polysaccharides

What type of reactions release energy?

Catabolic Exergonic Decomposition

Name four forms of energy important in human functioning

Chemical energy - used in chemical bonds Mechanical energy - directly powers the movement of matter Radiant energy - energy emitted and transmitted as waves Electrical energy - contributes to voltage changes

Distinguish between endergonic and exergonic reactions

Chemical reactions that absorb more energy than they release are endergonic The energy needed for endergonic reactions comes from exergonic reactions

Uracil

Contains nitrogen Is a pyrimidine Is found in RNA

What is true about chemical bonds?

Covalent bonds are stronger than ionic bonds

AB → A+B is a general notation for what type of reaction?

Decomposition

In DNA, nucleotide bonding forms a compound with what characteristic shape?

Double helix

Which part of an atom is responsible for reactions?

Electrons

Which of the following is a molecule, but not a compound? H2O 2H H2 H+

H2

C6H12O6 is the chemical formula for what?

Hexose monosaccharide

Which of the following combinations of atoms is most likely to result in a chemical reaction? Hydrogen and hydrogen Hydrogen and helium Helium and helium Neon and helium

Hydrogen and hydrogen

How do water molecules link via hydrogen bonds?

Hydrogen bonding occurs because the weakly negative oxygen atom in one water molecule is attracted to the weakly positive hydrogen atoms of two other water molecules

Distinguish between nonpolar and polar covalent bonds

In polar molecules, no region of the molecule is either more positive or more negative than any other A polar molecule is a molecule that contains regions that have opposite electrical charges

What is the characteristic that gives an element its distinctive properties?

Its number of protons

Distinguish between kinetic and potential energy

Kinetic energy is the form of energy powering any type of matter in motion Potential energy is the energy of position, or the energy matter possesses because of the positioning or structure of its components

On the periodic table of the elements, mercury (Hg) has an atomic number of 80 and a mass number of 200.59. It has seven stable isotopes. The most abundant of these probably have how many neutrons?

More than 80 neutrons each

A pentose sugar is a part of the monomer used to build which type of macromolecule?

Nucleic acids

Identify the building blocks of nucleic acids, and the roles of DNA, RNA, and ATP in human functioning

Nucleotides are compounds with three building blocks: one or more phosphate groups, a pentose sugar, and a nitrogen containing base DNA and RNA are nucleic acids that function in protein synthesis ATP is the body's fundamental molecule of energy transfer

CH4 is methane. What type of compound is it?

Organic compound

What are the four elements that make up more than 95 percent of the body's mass?

Oxygen Carbon Hydrogen Nitrogen

Describe an atom

Parts: Made up of small subatomic particles: protons, neutrons, and electrons Positive protons and neutral neutrons give mass to the atom The amount of electrons is equal to the amount of protons Properties: The smallest quantity of an element that retains the unique properties of that element Mutual attraction gives the atom some structural stability and a balanced charge

A molecule of ammonia contains one atom of nitrogen and three atoms of hydrogen. What are these linked with?

Polar covalent bonds

What type of energy is stored in a foot of snow on a steep roof?

Potential energy

Identify several factors that influence the rate of chemical reactions

Properties of the reactants (surface area) Temperature Concentration and pressure Enzymes and other catalysts

Chewing a bite of bread mixes it with saliva and facilitates its chemical breakdown. Why does this occur?

Saliva contains enzymes

A substance dissociates into K+ and Cl- in solution. What is the substance?

Salt

What type of ionic bond is a substance formed of crystals of equal numbers of cations and anions held together by?

Salt

Explain the role of salts in body functioning

Salts dissociate into ions. These ions are electrolytes; they are capable of conducting an electrical current in solution. This property is critical to the function of ions in transmitting nerve impulses and prompting muscle contraction

Which of the following is most likely to be found evenly distributed in water in a homogeneous solution? Sodium ions and chloride ions NaCl molecules Salt crystals Red blood cells

Sodium ions and chloride ions

What is the ability of an enzyme's active sites to bind only substrates of compatible shape and charge known as?

Specificity

Jenny mixes up a batch of pancake batter, then stirs in some chocolate chips. As she is waiting for the first few pancakes to cook, she notices the chocolate chips sinking to the bottom of the clear glass mixing bowl. What is the chocolate-chip batter is an example of?

Suspension

The bonding of calcium, phosphorus, and other elements produces mineral crystals that are found in bone. What type of reaction is this?

Synthesis

Describe the three basic types of chemical reactions

Synthesis reaction - A+B → AB Decomposition reaction - AB → A+B Exchange reaction - AB + C → A + BC

What happens to electrons as they jump to a higher level?

They gain energy and become less stable as they move away from the nucleus

Discuss four types of lipids important in human functioning

Triglycerides (fat) Phospholipids Steroids Prostaglandins (signaling molecules)

Ty is three years old and as a result of a "stomach bug" has been vomiting for about 24 hours. His blood pH is 7.48. What does this mean?

Ty's blood is slightly alkaline

Identify the properties of water that make it essential to life

Used as a lubricant and cushion Used as a heat sink Used as a component of liquid mixtures