Anatomy & Physiology I: Chapter 2

Water, pH, Organic Molecules, and Cell Functions

What is the importance of water and salts to body homeostasis?

Water is essential for maintaining body temperature, transporting nutrients, and facilitating biochemical reactions. Salts help in nerve transmission and muscle contraction.

What are examples of inorganic compounds?

Water, salts, many acids & bases (Don’t contain carbon)

What are examples of organic compounds?

Carbohydrates, lipids, proteins, and nucleic acids (Contain carbon w covalent bonds)

What are the only exceptions for inorganic compounds?

Carbon dioxide and Carbon dioxide

Why is water called the universal solvent?

Water can dissolve a wide variety of substances due to its polar nature, it being 60-80% of a cell's volume, and its role as the body’s major transport medium.

Define salts and the two types of ions formed from them when dissolved in water.

Salts are ionic compounds that dissociate into cations and anions when dissolved in water.

What is the difference between an acid and a base?

An ____ donates hydrogen ions (H+) in solution, while a ___ accepts hydrogen ions or donates hydroxide ions (OH-)

What are some important acids to remember?

Hydrochloric acid (HCL), acetic acid (HC₂H₃O₂), & carbonic acid (H₂CO₃)

What do Hydrochloric acid (HCL), acetic acid (HC₂H₃O₂), & carbonic acid (H₂CO₃) all have in common?

They are all acids and produce hydrogen ions when dissolved in water

What are some important bases to remember?

Bicarbonate (HCO₃⁻) and amonia (NH₃)

What does pH measure? Compare acidic, neutral, and basic pH values.

It measures the concentration of hydrogen ions in a solution. Acidic pH is less than 7, neutral is 7, and basic is greater than 7.

What do acids & bases regulate in the body?

They regulate pH

Would an acidic solution contain a higher, lower, or equal concentration of hydrogen ions?

It would contain a higher concentration of hydrogen ions and a lower concentration of hydroxide ions

Would a neutral solution contain a higher, lower, or equal concentration of hydrogen ions?

It would contain an equal concentration of hydrogen ions and an equal concentration of hydroxide ions

Would a basic solution contain a higher, lower, or equal concentration of hydrogen ions?

It would contain a lower concentration of hydrogen ions and a higher concentration of hydroxide ions

Define hydrolysis.

The chemical process of water breaking down a covalent bond in a compound, splitting the compound into two parts by adding the H from H₂O to one part, and the OH to the other

What is a monomer?

It’s a single building block of a polymer

What is a polymer?

A larger molecule made up of many monomers

What are the monomers of carbohydrates called? What are the polymers called?

They are called monosaccharides, and the polymers are called polysaccharides

Name a few carbohydrates and their functions.

Examples include glucose (the Cell’s energy source), deoxyribose & ribose (DNA & RNA), and glycogen (storage)

What are the building blocks and functions of lipids?

They are primarily made of fatty acids and glycerol. They serve functions such as energy storage, insulation, and forming cell membranes

Name the three classes of lipids and describe functions for each class.

1. Triglycerides (energy storage), 2. Phospholipids (cell membrane structure), 3. Steroids (cellular & hormonal functions)

What are the four parts of a triglyceride?

It consists of one glycerol molecule and three fatty acid chains

Do saturated fats contain any double bonds in their fatty acids?

They do not contain double bonds in their fatty acids

What are the two regions of a phospholipid?

It has a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails

How does the structure of a phospholipid make it ideal for formation of a lipid bilayer?

The hydrophilic heads face outward towards water, while the hydrophobic tails face inward, creating a bilayer that forms cell membranes, which keeps water out

What is the most common steroid and what are some of its functions?

It is the most common steroid, and it helps maintain cell membrane fluidity and serves as a precursor for steroid hormones

What are the monomers of proteins called?

They are called amino acids

Describe six general functions of proteins.

1. Enzymatic catalysis, 2. Structural support, 3. Transport, 4. Defense (antibodies), 5. Regulation (hormones), 6. Motion (muscle contraction)

What are the monomers of nucleic acids called?

They are called nucleotides

Compare DNA and RNA structures and functions.

DNA is double-stranded and stores genetic information, while RNA is single-stranded and plays roles in protein synthesis

What are the four bases found in DNA?

Adenine, guanine, cytosine, and thymine

What are the four bases found in RNA?

Adenine, guanine, cytosine, and uracil

Define complementary base pairing and its importance for DNA copying.

Complementary base pairing refers to the specific pairing of adenine with thymine and cytosine with guanine, which is crucial for accurate DNA replication

How is Adenosine Triphosphate (ATP) formed?

It’s formed through the breakdown of glucose

What is the role of ATP in cell metabolism?

It serves as the primary energy currency of the cell, providing energy for various biochemical processes

Why is ATP hydrolysis so important?

It releases energy that powers cellular activities and metabolic processes

In which organelle is most of the cell's ATP produced?

Most of the cell's ATP is produced in the mitochondria

What is dehydration synthesis?

A chemical reaction that joins two monomers together by forming a covalent bond, resulting in the removal of H₂O