E2 -Muscles, Chemistry, Homeostasis

What is matter?

Something that encompasses all substances in the environment that occupy space.

What is the periodic table?

The fundamental building blocks of the universe

What is mass?

The quantity of matter in an object.

How are mass and weight related?

At this level of study mass and weight are closely related

What example illustrates the relationship between mass and matter?

A pound of feathers and a pound of gold have identical mass but require vastly different volumes to achieve that mass.

What are atoms?

The smallest stable units of matter.

What three subatomic particles make up atoms?

Protons, neutrons, and electrons.

What is the charge of a proton?

Positive.

Where are protons located?

In the nucleus.

What is the relative size of protons?

Large compared to electrons.

What is the charge of a neutron?

Neutral (0).

Where are neutrons located?

In the nucleus.

What is the relative size of neutrons?

Large compared to electrons.

What is the charge of an electron?

Negative.

Where are electrons located?

Orbiting the nucleus.

What is the relative size of electrons?

The smallest of the three subatomic particles.

What determines atomic mass?

The combined number of protons and neutrons.

Why do electrons contribute little to atomic mass?

Because they are extremely small compared to protons and neutrons.

What are electron shells?

Energy levels where electrons orbit the nucleus.

How many electrons can the first shell hold?

2 electrons.

How many electrons can the second shell hold?

8 electrons.

How many electrons can the third shell hold?

8 electrons.

What is the valence shell?

The outermost electron shell of an atom.

Why is the valence shell important?

It determines the energy potential and reactivity of the atom.

What does an electron cloud drawing represent?

Electrons moving so rapidly that they appear as a cloud.

What do shell drawings show?

Electrons in fixed positions around the nucleus.

What is the atomic number?

The number of protons in an atom.

What is atomic mass?

The mass of protons plus neutrons.

Where is atomic mass found on the periodic table?

The bottom number (except hydrogen).

In a neutral atom, how are protons and electrons related?

The number of protons equals the number of electrons.

What are isotopes?

Atoms of the same element with different numbers of neutrons.

What is radioactive dating?

A method for determining the age of materials by measuring neutron loss in carbon isotopes.

What is the composition of modern carbon (Carbon-12)?

6 protons and 6 neutrons.

What happens to atoms over time in radioactive decay?

They lose neutrons.

What is an ionic bond?

A chemical bond formed by the transfer of one or more electrons.

What happens when sodium loses an electron?

It becomes Na⁺, a positive ion (cation).

What is a cation?

A positively charged ion formed when an atom loses electrons.

What is an anion?

A negatively charged ion formed when an atom gains electrons.

Why does chlorine easily gain an electron?

Because it has 7 electrons in its valence shell and needs one more for stability.

What happens when sodium transfers an electron to chlorine?

Sodium becomes Na⁺ and chlorine becomes Cl⁻.

What compound is formed when sodium and chlorine bond ionically?

Sodium chloride (NaCl).

What is a covalent bond?

A chemical bond formed by the sharing of electron pairs between atoms.

How does hydrogen achieve stability in bonding?

By sharing electrons with another atom.

What is a single covalent bond?

One shared electron pair.

What is a double covalent bond?

Two shared electron pairs (four electrons total).

Why is carbon uniquely versatile in bonding?

Its valence shell allows multiple bonding combinations with other elements.

What is a nonpolar molecule?

A molecule with symmetrical electron distribution and no charge difference.

Why is oxygen gas nonpolar?

Because both oxygen atoms are identical and share electrons equally.

What is a polar molecule?

A molecule with uneven electron distribution and partial charges.

Why is water polar?

Oxygen has greater electron density than hydrogen, creating partial negative and positive regions.

Which side of water is more negative?

The oxygen side.

Which side of water is more positive?

The hydrogen side.

How does valence shell status affect reactivity?

The more incomplete the shell, the more reactive the atom.

What happens when an atom has one electron in its valence shell?

It is highly reactive.

Which elements are examples of atoms with nearly empty valence shells?

Lithium and sodium.

What happens when the valence shell is half full?

The atom is moderately reactive.

What happens when the valence shell has 7 electrons?

The atom is highly reactive.

What happens when the valence shell is completely full?

The atom becomes chemically non-reactive (inert).

What are noble gases?

Elements with completely filled valence shells.

Which elements are noble gases?

Helium, neon, argon, krypton, xenon, and radon.

What does inert mean in chemistry?

Chemically non-reactive.

What determines differences between elements?

The number of protons in their atoms.

What happens when one proton and neutron are added to an atom?

It becomes a completely different element.

What happens when sodium loses an electron?

It becomes a positive ion (cation).

What happens when chlorine gains an electron?

It becomes a negative ion (anion).

What happens when sodium chloride dissolves in water?

It dissociates into Na⁺ and Cl⁻ ions.

What are monosaccharides?

Single sugar units; the simplest form of carbohydrates.

What are monosaccharides also called?

Simple sugars or monomers.

What are examples of monosaccharides?

Glucose and fructose.

What is glucose?

The primary energy molecule for cells.

What type of bond holds monosaccharides together?

Covalent bonds.

Do monosaccharides undergo ionic bonding?

No, they only share electrons.

What is the main role of carbohydrates?

To serve as the main energy source for cellular processes.

What process converts consumed molecules into glucose?

Glycolysis.

What happens to glucose after glycolysis?

It enters the Krebs cycle and electron transport chain to produce ATP.

What happens during insulin exhaustion?

The pancreas becomes overworked from constant glucose spikes.

What are polymers?

Large molecules built from repeating monomer units.

What are carbohydrate polymers called?

Polysaccharides.

What is the difference between simple sugars and complex carbohydrates?

Simple sugars release glucose immediately while complex carbohydrates release glucose gradually.

What foods are examples of simple sugars?

Candy and table sugar.

What foods are examples of complex carbohydrates?

Oatmeal and whole grains.

Why do complex carbohydrates provide sustained energy?

Because glucose units are released gradually during digestion.

What is dehydration synthesis?

A chemical reaction that removes water to form bonds between monomers.

What components make up the water removed during dehydration synthesis?

Two hydrogen atoms and one oxygen atom.

What is hydrolysis?

A chemical reaction that uses water to break polymers into monomers.

What happens to water during hydrolysis?

It is added to break the bond between molecules.

What happens when glucose and fructose undergo dehydration synthesis?

They form sucrose and release water.

What happens when sucrose undergoes hydrolysis?

It breaks into glucose and fructose.

Which macromolecules use dehydration synthesis and hydrolysis?

Carbohydrates, proteins, lipids, and nucleic acids.

What is glycogen?

The storage form of glucose in animals.

Where is glycogen stored in the body?

In muscle and liver tissues.

What are lipids?

Fats that serve as energy storage molecules and structural components.

What are saturated fats?

Fats with single covalent bonds between carbon atoms.

What are common sources of saturated fats?

Butter, cheese, meat, chicken, and ham.

What are unsaturated fats?

Fats with double covalent bonds between carbon atoms.

What physical property do unsaturated fats have?

More liquid and oily.

What are common sources of unsaturated fats?

Fish oil, avocado oil, coconut oil, and olive oil.

What causes the kink in unsaturated fatty acid chains?

Double covalent bonds.

Why are unsaturated fats easier for the body to metabolize?

Their structure prevents tight packing, making them easier to break down.

What are trans fats?

Unsaturated fats modified with additional double bonds that create a rigid linear shape.