Lesson 2: MED 107

Question 1

What is chemistry?

Answer 1

The science that deals with the elements, their compounds, and the chemical reactions that occur between them.

Question 2

What are the three main subatomic particles of an atom?

Answer 2

• Protons
• Neutrons
• Electrons

Question 3

What is the charge of protons?

Answer 3

Positive electrical charge (+1)

Question 4

Where are protons located in an atom?

Answer 4

In the nucleus

Question 5

What determines the atomic number of an element?

Answer 5

The number of protons in the nucleus

Question 6

What is the charge of neutrons?

Answer 6

Electrically neutral; no charge

Question 7

What role do neutrons play in an atom?

Answer 7

Contribute to the mass and stabilize the nucleus

Question 8

What is the charge of electrons?

Answer 8

Negative electrical charge (-1)

Question 9

Where do electrons orbit in an atom?

Answer 9

In regions called electron shells or energy levels

Question 10

What happens to an atom that gains electrons?

Answer 10

It becomes negatively charged (anion)

Question 11

What happens to an atom that loses electrons?

Answer 11

It becomes positively charged (cation)

Question 12

What defines an element?

Answer 12

A pure substance made up of only one type of atom

Question 13

What are isotopes?

Answer 13

Different forms of the same element with the same number of protons but different numbers of neutrons

Question 14

What is a compound?

Answer 14

A substance formed when two or more elements chemically bond together

Question 15

What is an ionic bond?

Answer 15

A bond formed when one atom gives up one or more electrons to another atom

Question 16

Provide an example of an ionic bond.

Answer 16

Sodium chloride (NaCl)

Question 17

What is a covalent bond?

Answer 17

A bond formed when atoms share electrons

Question 18

Provide an example of a covalent bond.

Answer 18

Water (H₂O)

Question 19

What are hydrogen bonds?

Answer 19

Intermolecular forces that form when a hydrogen atom covalently bonded to a more electronegative atom experiences attraction to another electronegative atom

Question 20

What is chemical energy?

Answer 20

Energy involved in the formation and breaking of chemical bonds

Question 21

What is the role of water (H₂O) in living organisms?

Answer 21

• Universal solvent
• Temperature regulation
• Transport
• Hydration

Question 22

What role does carbon dioxide (CO₂) play in living systems?

Answer 22

• Respiration waste product
• Photosynthesis input
• pH regulation

Question 23

What is the importance of molecular oxygen (O₂)?

Answer 23

• Essential for aerobic respiration
• Participates in metabolism
• Used by the immune system

Question 24

What is ammonia (NH₃)?

Answer 24

A colorless gas that occurs as a byproduct of protein and nucleic acid metabolism

Question 25

What are mineral salts and their importance?

Answer 25

Ions that help maintain cellular homeostasis and are crucial for various physiological functions

Question 26

What are the three types of carbohydrates?

Answer 26

* Monosaccharides * Disaccharides * Polysaccharides

Question 27

What are the roles of lipids?

Answer 27

* Energy storage * Membrane structure * Hormone production

Question 28

What are proteins made of?

Answer 28

Amino acids linked by covalent bonds known as peptide bonds

Question 29

What are the two types of nucleic acids?

Answer 29

* DNA (Deoxyribonucleic Acid) * RNA (Ribonucleic Acid)

Question 30

What is the role of ATP?

Answer 30

Energy currency of the cell

Question 31

What is diffusion?

Answer 31

The passive movement of molecules from an area of higher concentration to an area of lower concentration

Question 32

True or False: Diffusion requires energy.

Answer 32

False

Question 33

What is the function of the plasma membrane?

Answer 33

Regulates the movement of substances in and out of the cell

Question 34

What is the role of electron donors in chemical reactions?

Answer 34

Give up electrons during a chemical reaction

Question 35

What is the role of electron acceptors?

Answer 35

Accept electrons during a chemical reaction

Question 36

Fill in the blank: The process by which water is used to break down larger molecules during digestion is called _______.

Answer 36

Hydrolysis

Question 37

What is the primary source of energy for living organisms?

Answer 37

Carbohydrates

Question 38

What type of bond is formed between sodium and chlorine in sodium chloride (NaCl)?

Answer 38

Ionic bond

Question 39

What is the role of hydrogen bonds in water?

Answer 39

Help hold water molecules together and contribute to water’s unique properties

Question 40

What is diffusion?

Answer 40

The movement of molecules from an area of higher concentration to an area of lower concentration until they are evenly spread out.

Question 41

What is osmosis?

Answer 41

The movement of water molecules through a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Question 42

What factors affect diffusion?

Answer 42

* Temperature * Concentration Difference * Surface Area * Distance

Question 43

What occurs during oxygen and carbon dioxide exchange in the lungs?

Answer 43

Oxygen (O₂) diffuses from the air sacs into the bloodstream, while carbon dioxide (CO₂) diffuses from the blood into the air sacs.

Question 44

What is the definition of active transport?

Answer 44

The movement of molecules across a cell membrane from a lower concentration to a higher concentration, using energy (ATP).

Question 45

What is the main energy source required for active transport?

Answer 45

ATP

Question 46

What happens to red blood cells in a hypotonic solution?

Answer 46

Water enters the cell, causing it to swell and potentially burst.

Question 47

What happens to red blood cells in a hypertonic solution?

Answer 47

Water exits the cell, causing it to shrink.

Question 48

What is the pH scale used to measure?

Answer 48

The acidity or basicity of a solution on a scale of 0 to 14.

Question 49

What is the pH of a neutral solution?

Answer 49

7

Question 50

What is the optimal pH range for enzyme function?

Answer 50

Enzymes have a specific pH range in which they function best, and deviations can decrease their activity.

Question 51

What is a buffer?

Answer 51

Substances that help maintain a stable pH in a solution by neutralizing small amounts of acids or bases.

Question 52

What is the role of the sodium-potassium pump?

Answer 52

It moves sodium (Na⁺) out of the cell and potassium (K⁺) into the cell, essential for nerve signaling and muscle contractions.

Question 53

Fill in the blank: Osmosis is a _______ process, meaning it does not require energy (ATP).

Answer 53

passive

Question 54

What is the difference between cations and anions?

Answer 54

* Cations are positively charged ions * Anions are negatively charged ions

Question 55

What is a covalent bond?

Answer 55

A type of chemical bond formed when two atoms share one or more pairs of electrons.

Question 56

What happens to blood pH levels during homeostasis?

Answer 56

Blood pH is tightly regulated around 7.4.

Question 57

What type of bond occurs when one atom transfers electrons to another atom?

Answer 57

Ionic bond

Question 58

What is an isotope?

Answer 58

Variants of a chemical element with the same number of protons but different numbers of neutrons.

Question 59

What are purine bases in nucleic acids?

Answer 59

* Adenine (A) * Guanine (G)

Question 60

What are pyrimidine bases in DNA?

Answer 60

* Thymine (T) * Cytosine (C)

Question 61

True or False: Diffusion requires energy input.

Answer 61

False

Question 62

What is chemical energy?

Answer 62

A form of potential energy stored in the bonds of chemical compounds, released or absorbed during chemical reactions.

Question 63

What is the mass number of an atom?

Answer 63

The total number of protons and neutrons in the nucleus of an atom.

Question 64

What is hydrolysis?

Answer 64

A chemical reaction in which water is used to break down larger molecules into smaller ones.