Chemical Basis of Life

Question 2

What components make up the atomic structure?

Answer 2

The nucleus, which contains protons and neutrons. Electron shells surround the nucleus and contain electrons.

Question 3

What charge is associated with an electron and what type of ion is it?

Answer 3

An electron is negatively charged and referred to as an anion.

Question 4

What charge is associated with a proton and what type of ion is it?

Answer 4

Protons are positively charged and are referred to as cations.

Question 5

What does ionization refer to?

Answer 5

Ionization is the transfer/exchange of elections from one element to another.

Question 6

Which electron shell contains the most potential energy?

Answer 6

The outer most shell contains the most potential energy because it is furthest from the nucleus; thus having less “pull” from the positively charged proton(s). With this, electrons are more easily released from the outer shell and can ionize with another element.

Question 7

Why is it so important to replace water over electrolytes during a workout that produces heavy sweating?

Answer 7

Hydrogen and oxygen (which when bonded, form the molecule H2O) are two of the body’s most abundant and vital elements for the body’s physiological reactions to occur). When sweating, water is lost at a high rate and needs to be replaced so the body can carry out its functions. Although electrolytes are lost during sweating, the rate off loss is not as high and the body’s composition is not as “dependent” on the elements that make up electrolytes.

Question 8

Gastric acid has a pH of ___________.

Answer 8

The pH of gastric acid is very low, approximately 2.

Question 9

Why do antacids such as Tums, Gaviscon, milk of magnesia, etc., decrease the symptoms associated with gastric reflux?

Answer 9

Antacids, such as the ones listed, are basic solutions. This means that the pH is approximately 12. When these drugs interact with gastric acid in the esophagus, they counteract the acidity (pH of approximately 2) because of their basic property.

Question 10

Blood is best described as a ___________ mixture.

Answer 10

Blood is best described as a suspension because of the size of the particles contained in it. These particles are so large, that when they are agitated (centerfuged) the particles separate from the plasma (water).

Question 11

Why do we relate and associate physiologic reactions in the body to water?

Answer 11

Water makes up over 60% of our body composition. It has a neutral pH (7). Therefore, water is considered the set point of measuring pH. Water also is the source of heat management (normal 98.6 F); water temperature in the body can raise during extreme exercise causing a reaction to rid itself of this heat through sweating (primarily water).

Question 12

What is a calorie?

Answer 12

A calorie is a description of energy. It is described as the ability (energy) needed to raise 1 gram of water 1 degree Celsius. Calories vary depending on the source they come from. Therefore, calories associated with fat take longer to raise the temperature of 1 gram of water while calories from carbohydrates require less energy to raise 1 gram of water 1 degree Celsius.

Question 13

Why does the body need water? In other words, what are its functions?

Answer 13

Water is needed to dissipate heat, in the transportation of nutrients/wastes (via the blood/urine), and to breakdown elements for proper use.

Question 14

What are the major elements of the body?

Answer 14

OxygenHydrogenNitrogenPhosphorusCarbonCalciumThese elements make up about 98% of body weight.

Question 15

What are electrolytes and why are they essential?

Answer 15

Electrolytes are compounds and molecules that ionize in water. They are referred to as salts that form solutions with water capable of producing electrical charges/activity. Electrolytes are needed for muscle and nerve functions. When depleted below normal levels, muscle cramps, bone density, and cognitive functions suffer; coma and death can even occur.

Question 16

What are free radicals and what causes them?

Answer 16

Free radicals are elements present in the body that carry an odd number of electrons. The body identifies free radicals as foreign and threading to the body. In response, the body attacks the free radicals with more elements (free radicals) Causing damage to good tissue. This process begins to lay down additional tissue known as a mass/tumor to help replace the damaged tissue. However, this new tissue is made up of even more free radicals, which causes the cycle to continue out of control (the tumor grows). Free radicals can be triggered by metabolic reactions, radiation, and chemicals.

Question 17

A solution that is hydrophilic is one the _________.

Answer 17

Is charged and devolves well in water.

Question 18

What does pH measure?

Answer 18

pH measures the concentration of hydrogen ions in a solution.

Question 19

Fat is considered hydrophobic. What does this mean?

Answer 19

Hydrophobic substances do not easily dissolve in water. The opposite is true of hydrophilic substances; these substances dissolve easily in water.

Question 20

There are several ways in which substances can mix in water. What are they?

Answer 20

Solutions, colloids, and suspensions

Question 21

What are the physical characteristics of a suspension?

Answer 21

Particles are large and are not able to pass through membranes (e.g., blood vessels). They will separate upon standing. An example is blood. The particles that separate out upon standing are RBC, WBC, and Plasma. These substances are too large to pass through the vessel walls in the body.

Question 22

Describe the difference between an acid and a base.

Answer 22

An acid is a proton donor and has a pH less than 7. A base is a proton acceptor and has a pH higher than 7.

Question 23

Provide an example of potential energy.

Answer 23

Potential energy is any inherent substance that has the ability to create energy. An example is glucose; it can be used as energy to move muscle, but until it is used, it is considered potential energy.

Question 24

Chemical energy is responsible for many reactions in the body that create the ability to do work. Describe the three ways chemical reactions can create energy in our body.

Answer 24

Decomposition is the process of breaking down molecular bonds.
Synthesis reactions occur when molecular bonds bind together to form a new bond.
Exchange reactions occur when molecular compounds exchange elements.

Question 25

What can effect reaction rates of chemical reactions?

Answer 25

1. Concentration of a substance: the more concentrated a substance, the more collisions occur, which increase the reaction rate.
2. Temperature: as temperature rises in a substance, the greater the collision force, which increases the reaction rate.
3. Catalysts: catalysts are enzymes (i.e., a chemical that speeds up a reaction rate).

Question 26

Describe the two different types of metabolism.

Answer 26

Catabolism is the breakdown or decomposition of molecular compounds.
Anabolism is the synthesizing or building up of molecular compounds.

Question 27

Where is glucose stored?

Answer 27

Glucose is stored as glycogen primarily in the liver, muscles, and blood. The highest concentrations of glycogen are found in the muscle.

Question 28

Which of the organic compounds is most easily broke down for energy?

Answer 28

Carbohydrates are most easily broke down for energy. Further, monosaccharides are the simplest of carbohydrates; all other saccharides (disaccharides and polysaccharides) must be broken down to this simplest form (monosaccharides) to be utilized as energy.

Question 29

List functions of lipids.

Answer 29

Energy storage, energy, organ protection, fill space in the body, maintain body/organ temperature, structure.

Question 30

Other than providing structure, be familiar with other functions of proteins.

Answer 30

Proteins function as communicators; as either hormones or cell receptors. Proteins can also act as a means by which substances can be transport across a membrane. In this capacity, proteins form channels. Proteins also function as catalysts (enzymes). These proteins act to help speed reactions. Proteins can also act to recognize and protect the body against foreign particles. Proteins also help with movement (i.e., muscle movement). Lastly, proteins act to bind cells to each other.