Human Anatomy & Physiology Chapter 2

Questions and Answers

What is the maximum number of electrons that the 3rd shell can effectively hold?

18 (correct)

Which atomic feature defines the identity of an element?

Number of Electrons

Mass Number

Atomic Number (correct)

Number of Neutrons

Which of the following elements is represented by the chemical symbol 'Na'?

Nitrogen

Calcium

Sodium (correct)

Natrium

Which of these elements is NOT one of the four major elements in the human body?

Iron Signup and view all the answers

How are elements organized in the periodic table?

By increasing atomic number Signup and view all the answers

What is the total number of major elements that make up 96% of the human body?

4 Signup and view all the answers

Which shell is closest to the nucleus and can hold a maximum of 2 electrons?

1st shell Signup and view all the answers

What does the atomic number indicate about an element?

The number of protons Signup and view all the answers

Which type of bond is considered the strongest among chemical bonds?

Covalent bond Signup and view all the answers

What distinguishes a hydrophilic compound from a hydrophobic compound?

Hydrophilic compounds attract water molecules while hydrophobic compounds do not. Signup and view all the answers

What is the primary function of enzymes in biological systems?

To catalyze metabolic reactions. Signup and view all the answers

What is the nature of a radioisotope?

It emits radiation due to an unstable nucleus. Signup and view all the answers

What defines an organic compound?

It contains carbon atoms primarily bonded to hydrogen. Signup and view all the answers

What characterizes a buffer solution?

It can maintain a stable pH level despite the addition of acids or bases. Signup and view all the answers

What is the difference between an anion and a cation?

An anion has gained electrons while a cation has lost electrons. Signup and view all the answers

Which of these accurately describes salts in a biological context?

Salts are ionic compounds that dissociate into ions in solution. Signup and view all the answers

What is the nature of hydrogen bonds?

Weak attractions between partially positive and partially negative ends of molecules. Signup and view all the answers

How do hydrogen bonds influence surface tension in water?

They enable polar water molecules to be more attracted to each other than to nonpolar air molecules. Signup and view all the answers

Which is true about chemical reactions?

They can result in the formation, breaking, or rearranging of bonds. Signup and view all the answers

In a reversible chemical reaction, what indicates that the reaction can proceed in either direction?

Two arrows pointing in opposite directions. Signup and view all the answers

What characterizes endergonic reactions?

They require input of energy from another source. Signup and view all the answers

What role do hydrogen bonds play in the structure of proteins?

They contribute to maintaining the tertiary and quaternary structures. Signup and view all the answers

Which of the following statements about surface tension is true?

Surface tension makes rain fall in droplets. Signup and view all the answers

Why can insects walk on water?

Surface tension created by hydrogen bonds allows them to distribute their weight. Signup and view all the answers

What happens to the hydrogen ion concentration when the pH of a solution decreases by one unit?

It increases by 10 times. Signup and view all the answers

Which of the following accurately describes a solution with a pH below 7?

It is acidic with hydrogen ions outnumbering base ions. Signup and view all the answers

What can be inferred about a solution with a pH of 7?

It is neutral. Signup and view all the answers

What is the role of a buffer in a chemical system?

To stabilize the pH despite the addition of acids or bases. Signup and view all the answers

Which statement is true about blood pH?

It has a narrow range of 7.35 to 7.45. Signup and view all the answers

What type of compound is formed when metals and nonmetals bond ionically?

Salts Signup and view all the answers

What characterizes a solution with a high concentration of base ions?

It is basic or alkaline with a pH greater than 7. Signup and view all the answers

How does a single-digit change in pH relate to the negative logarithm of the hydrogen ion concentration?

It corresponds to a 10-fold change in hydrogen ion concentration. Signup and view all the answers

What is the primary function of glycogen in the human body?

To serve as the primary storage form of glucose Signup and view all the answers

Which type of fatty acid is typically solid at room temperature?

Saturated fatty acids Signup and view all the answers

What distinguishes polyunsaturated fatty acids from other types of fatty acids?

They contain two or more double bonds between carbon atoms. Signup and view all the answers

Which type of polysaccharide is indigestible by humans and is not a source of energy?

Cellulose Signup and view all the answers

What is a characteristic of omega-3 fatty acids?

They must be consumed through the diet. Signup and view all the answers

How do monounsaturated fatty acids differ from saturated fatty acids?

Monounsaturated fatty acids contain one double bond between two carbons. Signup and view all the answers

Which type of lipid molecule is primarily hydrophobic?

Triglycerides Signup and view all the answers

Which of the following is a consequence of overconsumption of saturated fats?

Increased risk of cardiac disease Signup and view all the answers

Study Notes

Atoms and Atomic Structures

Atoms consist of a nucleus surrounded by electron shells, with each shell holding a defined number of electrons.
The first shell holds 2 electrons, the second holds 8, and the third can hold up to 18 but typically is satisfied with 8.
More complex atoms may have additional electron shells.

Elements and Atomic Number

An element is a substance that cannot be broken down chemically; each element has a unique atomic number based on the number of protons it contains.
The periodic table organizes elements by increasing atomic number, with symbols derived from the element's name or its Latin/German name.

Composition of the Human Body

The human body is primarily composed of four major elements: hydrogen, oxygen, carbon, and nitrogen (96% total).
Contains 7 mineral elements and 13 trace elements essential for various bodily functions.

Chemical Bonds

Hydrogen bonds are weak attractions between partially charged atoms, crucial for properties like water's surface tension.
Strongest chemical bonds include covalent bonds, followed by ionic and hydrogen bonds.

Chemical Reactions

Each chemical reaction involves the formation, breaking, or rearrangement of bonds, with reactants converted into products.
Exergonic reactions release energy, while endergonic reactions require energy to proceed.

Acids, Bases, and pH

A pH of 7 indicates a neutral solution; pH < 7 indicates acidity and pH > 7 indicates basicity.
Buffers, composed of a weak acid and its corresponding base, maintain stable pH levels in biological systems.

Electrolytes and Salts

Salts are formed from the reaction of metal cations and nonmetal anions due to ionic bonding.
When dissolved in water, salts dissociate into electrolytes which conduct electrical currents.

Organic Compounds

Carbohydrates include monosaccharides and polysaccharides like glycogen (glucose storage) and cellulose (indigestible fiber).
Lipids are hydrophobic molecules composed mainly of carbon and hydrogen, including fatty acids categorized into saturated, monounsaturated, and polyunsaturated types.
Proteins serve numerous functions in the body, shaped by their amino acid sequences and structures.

Enzyme Function

Enzymes are specialized proteins that speed up metabolic reactions, crucial for regulating biochemical pathways.

Nucleic Acids

Nucleic acids, such as DNA and RNA, are essential for genetic information storage and transfer.

Energy Considerations in Reactions

Changes in pH are logarithmic; a pH decrease by one unit implies a tenfold increase in hydrogen ion concentration.
Proper understanding of pH is vital for maintaining homeostasis in biological systems.

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This quiz explores the fundamental concepts of atomic structures and their significance in the chemistry of life, as presented in Chapter 2 of Human Anatomy & Physiology. Perfect for students looking to reinforce their understanding of the basic building blocks of matter and their roles in biological systems.