Essential Chem. for biology (Lecture 3)

Question 1

Element

Answer 1

Substance that cannot be broken down or converted to another substance by chemical means.

(While elements are made up of many identical atoms, it’s important to note that these atoms are already in their simplest form for that element. You can’t break them down into smaller, different elements through chemical reactions. )

Question 2

atom

Answer 2

Basic structural unit of matter

Question 3

Molecule

Answer 3

Two or more atoms joined by chemical bonds (can be the same or different) e.g., water (H20), oxygen gas (O2)

Question 4

Compound

Answer 4

A compound is a type of molecule, in which the types of atoms forming the molecule are different from each other. E.g., carbon dioxide (CO2), propane (C3H8)

Question 5

What are the basic components of an atom

Answer 5

Proton: positive charge, Determines element

Electron: negative charge, participates in chem. reactions, outer shell electrons determine chemical behavior

Nucleus: consists of neutrons and protons

Question 6

Elements are determined by the number of _______ (atomic number)

Answer 6

protons

Question 7

The _______ of an atom is the sum of the protons and neutrons

Answer 7

atomic weight

Question 8

where is the protons and neutrons and electrons found?

Answer 8

protons and neutrons (no electric charge) are found in the nucleus

electrons surround the nucleus

Question 9

what are ions

Answer 9

An ion is an atom or a molecule that has an electric charge. This charge is the result of gaining or losing electrons.

Question 10

Isotopes

Answer 10

Isotopes are versions of the same element, like different “editions” of an element, that have a different number of neutrons in their nuclei. However, they all have the same number of protons.

Question 11

What are the most important molecules

Answer 11

For biological molecules, the most important are carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P), and sulfur (S).

These elements are commonly found in biomolecules such as carbohydrates, lipids, proteins, nucleic acids, and other essential compounds that make up living organisms.

Question 12

What molecules make up the human body

Answer 12

Oxygen (#1) , Hydrogen and Nitrogen

Question 13

How can many health conditions are related to deficiencies of certain trace elements

Question 14

The number and organization of _____ determine the chemical behavior of an element

Answer 14

electrons

Question 15

_______ are organized in shells. The outer shell is where the action happens

Answer 15

electrons

Question 16

what are noble gases

Answer 16

They have full electron shells, meaning their outermost electron shells are completely filled with electrons, making them highly stable and unreactive with other elements (two electrons in the case of Helium, eight for the others).

Question 17

What is metabolism?

Answer 17

Metabolism is like the engine that keeps living things running. It’s the combination of all the chemical reactions happening inside our bodies and cells. These reactions help us do everything we need to survive, like getting energy from food, growing, and staying healthy.

So, when we talk about metabolism, we’re talking about all the ways our bodies use and change molecules to keep us alive and functioning.

Question 18

How do you form chemical bonds?

Answer 18

atoms form chemical bonds, either by sharing or transferring electrons, all to achieve a stable and happy electron configuration in their outermost shells.

Atoms can share or transfer elections to get to 2 or 8 electrons by forming chemical bonds

Question 19

Ionic bonds

Answer 19

involve a transfer if electrons and form between oppositely charged atoms

Question 20

Covalent bonds

Answer 20

involve sharing of electrons and form between uncharged atoms

Uncharged atoms, have an equal number of protons (positively charged) and electrons (negatively charged). As a result, the positive and negative charges balance each other out

Question 21

Whats more stronger, Ionic bonds or Covalent bonds?

Answer 21

Covalent bonds

Question 22

whats the difference between a covalent bond and ionic bond and what does that look like?

Answer 22

Covalent bonds : share of electrons
Ionic bond: Transfer of electrons

Question 23

In _____ bonds, electrons are transferred (donated and accepted) resulting in the formation of_____. ____ are atoms that are electrically charged.

Answer 23

ions

Question 24

What are Nonmetallic atoms

Answer 24

They include elements like oxygen (O), nitrogen (N), carbon (C), and many others. These atoms tend to have properties like being poor conductors of heat and electricity and often gaining or sharing electrons in chemical reactions.

Question 25

What is polar and nonpolar

Answer 25

Nonpolar
(Think of nonpolar molecules as twins. The atoms in these molecules are the same, like two identical siblings.)
No charge
H2 or C2

Polar
(Polar molecules are more like big brother and little brother. One atom is larger (has more electrons) than the other, creating an imbalance.)

Have a charge
H2O

Question 26

When a covalent bond forms between two atoms of the same element (e.g., oxygen gas, O2 ) the resulting bond is ______

Answer 26

non-polar

Question 27

What is electronegativity?

Answer 27

Electronegativity is a measure of an atom’s tendency to attract electrons in a chemical bond. It’s like how some elements “pull” on electrons more strongly than others. The higher the electronegativity of an atom, the more it attracts electrons toward itself.

Question 28

what has a charge and what doesn’t have a charge in polar and non-polar molecules?

Answer 28

polar has a charge

Non-polar doesnt have a charge

Question 29

Water is a ______ molecule

Answer 29

Polar

This polarity of water is responsible for many of its unique properties, such as its ability to form hydrogen bonds with other polar molecules, its high heat capacity, and its excellent solvent properties.

Question 30

Cohesion

Answer 30

water molecules stick to one another

Question 31

Adhesion

Answer 31

water molecules stick to other polar surfaces

(A surface is considered polar if it contains molecules or materials that have atoms with significantly different electronegativities (the ability to attract electrons)

Question 32

How is cohesion important for trees

Answer 32

Cohesion is responsible for trees moving water from their roots to the leaves where photosynthesis occurs.

Question 33

What is an example of Adhesion?

Answer 33

An example of adhesion is when water molecules stick to the inside surface of a glass or a tube.

Question 34

How does water have a high degree of surface tension?

Answer 34

Water has a high degree of surface tension due to its unique molecular properties, specifically its cohesive and adhesive forces

Question 35

Water is an extremely good _____

Answer 35

Water is an extremely good solvent

Question 36

what is a solvent?

Answer 36

a substance, typically a liquid, that has the ability to dissolve other substances

Question 37

How can water dissociate?

Answer 37

Water can dissociate, meaning it can break apart into ions

Question 38

Explain the Ph scale

Answer 38

The pH scale is a way to measure how acidic or basic a substance is. It goes from 0 to 14, with 7 being neutral (neither acidic nor basic).

Acidic: Anything below 7 on the pH scale is acidic. Examples include lemon juice and vinegar.

Neutral: 7 on the pH scale is neutral, like pure water.

Basic: Anything above 7 is basic (also called alkaline). Examples include baking soda and soap.

Question 39

The hydrogen bonds in water help to ______ temperatures

Answer 39

Moderate

It means that the hydrogen bonds in water act like a temperature regulator. They make it harder for water to heat up or cool down quickly. So, water can absorb and release heat slowly, helping to keep temperatures more stable in the environment, like a natural thermostat.

Question 40

How can hydrogen bonds in water help moderate tem?

Answer 40

Water can absorb large amounts of energy without large changes temperature (High specific heat). This is because energy is first used to break Hydrogen bonds

Question 41

What is specific heat?

Answer 41

is a measure of how much heat a certain amount of a substance (like a material or substance) needs to absorb to get hotter by a certain amount. In simpler terms, it tells us how easily a substance can heat up when we add heat to it.

Question 42

Why does ice float?

Answer 42

Ice is less dense than liquid water

When we say that ice is less dense than liquid water, we mean that a given volume of ice has fewer water molecules packed into it compared to the same volume of liquid water. In other words, ice is less tightly packed.

Question 43

What happens if ice didn’t float?

Answer 43

If ice didn’t float, ponds and lakes would freeze from the bottom

Question 44

Thermal expansion

Answer 44

The expansion of warming oceans was the main factor contributing to sea level rise, in the 20th Century, and currently accounts for more than half of the observed rise in sea levels

thermal expansion is the tendency of materials to change in size with changes in temperature

Question 45

Ice sheets

Answer 45

These vast reserves contain billions of tonnes of frozen water - if the largest of them (the East Antarctic ice sheet) melts, the global sea level will rise by an estimated 64m

Question 46

whats the difference between atoms and elements

Answer 46

Atom: Think of an atom as the tiniest building block of matter. It’s like a single brick in a wall.

Element: An element is like a unique type of brick. It’s made up of many identical atoms.

Question 47

what is the difference between a element and compound? and what are they both classified as

Answer 47

If the atoms in a substance are identical, it’s an element. If the substance consists of different types of atoms chemically bonded together
(molecules)