Biological Chemistry and Macromolecules

Flashcards covering mixtures, chemical reactions, inorganic compounds (water, salts, acids, bases), and organic compounds (carbohydrates, lipids, proteins, ATP) from the lecture notes.

What is a mixture?

A substance containing two or more components that are physically intermixed with each other.

What are the three types of mixtures?

Solutions, colloids, and suspensions.

Describe a solution.

A homogenous mixture of very small particles that do not settle out, with components evenly distributed.

In a solution, what is the solvent?

The medium by which the solute dissolves, with water being the body's primary solvent.

How is percent solution determined?

The amount of solute dissolved expressed as a percentage of the total solution volume.

What is molarity?

The number of moles of solute present per liter of total solution.

Describe a colloid.

A heterogeneous mixture composed of large solute particles that do not settle out, capable of sol-gel transformation.

What is sol-gel transformation?

The process where a colloid changes from a fluid state to a more solid state and back again, such as the cytosol of cells.

Describe a suspension.

A heterogeneous mixture composed of large solute particles that do settle out, like blood where cells settle to the bottom.

When do chemical reactions occur?

When chemical bonds are formed, broken, or rearranged.

What is a synthesis reaction?

A reaction that forms bonds between atoms or molecules to create larger, more complex structures, also known as anabolic reactions.

What is a decomposition reaction?

A reaction that breaks down bonds between atoms and molecules to create smaller units, also known as catabolic reactions.

What is the primary difference between organic and inorganic compounds?

Organic compounds are composed of carbon with H, O, N, P, or S bonds and are found in living things, while inorganic compounds are found in nonliving things and can be made of metals, salts, or simple ions.

What percentage of total body mass does water make up?

Most of the total body mass and most of the volume of individual cells.

What does it mean for water to be a universal solvent?

It transports gases, nutrients, and wastes dissolved in it as part of the blood and can surround charged structures to prevent interactions through hydrolysis.

Why does water have a high heat capacity?

It can absorb or release large amounts of heat with little change to its own temperature, helping to maintain body temperature for homeostasis.

How does water protect our internal organs?

It provides a cushion for internal organs to prevent damage.

What is hydrolysis?

A decomposition reaction that adds water into a larger molecule to break it into smaller pieces, important for digestion and nutrient absorption.

What do salts dissociate into in solution?

Electrolytes, which are charged ions in water that allow for different body functions like muscle contraction, nerve impulses, and oxygen transport.

How do acids and bases affect pH?

Acids release H+ ions, causing pH to drop, while bases release OH- ions or absorb H+ ions, causing pH to increase.

What is the optimal pH range for the human body?

Around 7.35-7.45.

What are buffers and their function?

Weak acids or bases that prevent large changes in pH by releasing H+ or absorbing excess H+ when needed.

Why is carbon essential for organic molecules in the body?

It is electroneutral, neither gaining nor losing electrons, and can form molecules of various shapes and specific functions (chains or rings).

What are macromolecules?

Polymers made up of several smaller, identical subunits called monomers.

What is the monomer of carbohydrates?

Monosaccharides, which include glucose, fructose, and galactose.

What is the primary function of carbohydrates in the body?

A fast, easy-to-use energy source for ATP synthesis and for cell communication on the cell surface.

What are the three main types of lipids?

Triglycerides, phospholipids, and steroids.

What are triglycerides composed of and what is their function?

Fatty acids and glycerol, formed under the skin to store energy, provide insulation, and protect organs.

Describe saturated fats.

Contain only single, covalent bonds between molecules, are packed closely, are solid at room temperature, and can build up in blood vessels.

Describe unsaturated fats.

Contain one or more double covalent bonds, have more spread-out molecules, and are typically liquid at room temperature (e.g., plant-based oils).

Why are trans fats considered the worst type of fat?

They have a hydrogen added at double bond sites, can build up in blood vessels, and lead to various health problems.

What are phospholipids composed of and how do they interact with water?

Modified triglycerides with two fatty acid chains and a phosphate group; the phosphate head is hydrophilic (interacts with water), and the fatty acid tails are hydrophobic (do not interact with water).

What is the most important steroid for life?

Cholesterol, used as a base to form other steroids like testosterone, estrogens, and corticosteroids.

What is the monomer of proteins?

Amino acids, which form specific sequences leading to varied functions.

Describe fibrous proteins.

Long strands that link together to form stable structures, providing strength (e.g., collagen fibers).

Describe globular proteins.

Compact, spherical, and chemically active; they transport molecules, help the immune system, and regulate growth and development.

What is the function of enzymes?

Biological catalysts that lower the activation energy of chemical reactions, speeding them up to sustain life.

What is ATP?

Adenosine Triphosphate, the energy-transferring molecule of any body cell, created by glucose.

How does ATP transfer energy?

Its triphosphate tail, with high bond energy, is transferred to another molecule, temporarily giving that molecule more energy to do work.

Why is ATP constantly regenerated and not stored?

It is used, then immediately regenerated because without it, chemical reactions would stop and muscles could not contract, leading to death.