Chemistry Of Life Flashcards
What is a chemical element?
A pure substance that consists entirely of one kind of atom
Elements are represented by one- or two-letter symbols, such as C for carbon and H for hydrogen.
What is the atomic number of an element?
The number of protons in the nucleus of an element
For example, carbon has an atomic number of 6.
What six elements make up about 99 percent of the mass of living things?
- Calcium
- Carbon
- Hydrogen
- Oxygen
- Nitrogen
- Phosphorus
These elements are essential for life.
What are trace elements?
Elements that make up the remaining 1 percent of mass in living organisms
A lack of trace elements can stunt plant growth or damage developing organs in unborn animals.
What affects how atoms interact with each other?
The number of electrons in their outer shells
The outer shell can be thought of as the ‘face’ an atom shows to its neighbors.
What are isotopes?
Atoms of the same element that differ in the number of neutrons
For example, carbon-14 has 8 neutrons while all carbon atoms have 6 protons.
What is the mass number of an atom?
The total number of protons and neutrons in the nucleus
Isotopes are identified by their mass numbers.
What is atomic mass?
The weighted average of the masses of an element’s isotopes
The abundance of each isotope in nature is considered when calculating the average mass.
Do neutrons affect the chemical properties of an isotope?
No, neutrons do not affect the chemical properties
Isotopes have different masses but their chemical properties remain the same.
How many protons and electrons does Carbon-12 have?
6 protons and 6 electrons
Carbon-12 is one of the nonradioactive isotopes.
What is the relationship between protons and electrons in a neutral atom?
They are equal in number
This balance maintains electrical neutrality in the atom.
What is the smallest unit of most compounds?
A molecule
A molecule is formed when atoms are joined together by covalent bonds.
What type of bond is formed when atoms share one electron from each atom?
A single covalent bond
This type of bond involves the sharing of one pair of electrons.
In a water molecule, how many electrons does each hydrogen atom share?
Two electrons
Each hydrogen atom in a water molecule shares one electron with oxygen.
What bond is formed when one atom loses an electron and another atom gains it?
An ionic bond
This bond involves the transfer of electrons, resulting in oppositely charged ions.
What happens to a neutral atom that loses electrons?
It becomes positively charged
A neutral atom loses its electrical neutrality and becomes a cation.
How are covalent bonds different from ionic bonds?
Covalent bonds involve sharing electrons, while ionic bonds involve transferring electrons
The nature of electron interaction differentiates the two types of bonds.
Fill in the blank: The electrons in an atom’s outer shell that are available to form bonds are called _______.
valence electrons
Valence electrons play a critical role in bond formation.
True or False: Ionic bonds form between atoms of the same charge.
False
Ionic bonds form between oppositely charged ions.
What do you call atoms that have gained or lost electrons?
Ions
Ions can be positively charged (cations) or negatively charged (anions).
What type of bond is formed when atoms share four electrons?
A double bond
A double bond involves the sharing of two pairs of electrons.
What type of bond is formed when atoms share six electrons?
A triple bond
A triple bond involves the sharing of three pairs of electrons.
What are van der Waals forces?
Weak attractions between molecules when they are very close together
Van der Waals forces are crucial for interactions among molecules in living cells, allowing for temporary connections that facilitate various biological processes.
What is the role of weak interactions in living cells?
They allow molecules to interact briefly for signaling, chemical reactions, or information transfer
Weak interactions are crucial for processes like enzyme activity and cellular communication.
What is a hydrogen bond?
A weak bond formed between a hydrogen atom of one molecule and an oxygen or nitrogen atom of another molecule
Hydrogen bonds are significant for the properties of water and biological molecules like DNA.
What does a chlorine atom do to become a chloride ion?
It tends to gain one electron
This gain of an electron results in a negatively charged ion, which is essential for forming ionic compounds.
What are the differences between ionic bonds and covalent bonds?
Ionic bonds involve transfer of electrons, while covalent bonds involve sharing of electrons
These differences affect the properties and behavior of the resulting compounds.
Describe the major subatomic particles that make up an atom.
Protons, neutrons, and electrons
Protons are positively charged, neutrons are neutral, and electrons are negatively charged.
Why do isotopes of an element have the same chemical properties?
They have the same number of electrons
The chemical properties are primarily determined by the electron configuration, which remains unchanged among isotopes.
How do the physical and chemical properties of a compound compare to those of the elements it is composed of?
They can be very different
The properties of compounds often differ significantly from the properties of the individual elements due to the nature of chemical bonding.
What does the presence of liquid water on a planet suggest?
That life may be present
What is the chemical formula for water?
H2O
What unique state is water found in over most of Earth’s surface?
Liquid state
What causes water to have a partial negative charge on one end?
Oxygen nucleus attracts electrons more strongly than hydrogen nuclei
What term describes a molecule with unevenly distributed charges?
Polar
What type of bond is formed between a hydrogen atom with a partial positive charge and another atom with a partial negative charge?
Hydrogen bond
Fill in the blank: A molecule in which the charges are unevenly distributed is said to be _______.
Polar
True or False: Water molecules can attract each other due to their partial charges.
True
What is the significance of hydrogen bonds in water?
They give water unique characteristics, such as expanding upon freezing and dissolving many substances
Hydrogen bonds are weaker than covalent or ionic bonds but are crucial for water’s properties.
What property of water allows it to expand slightly upon freezing?
Hydrogen bonding
This property makes ice less dense than liquid water.
Define cohesion in the context of water.
The attraction between molecules of the same substance
In water, cohesion occurs because a single molecule can form multiple hydrogen bonds.
What phenomenon causes water to form beads on a smooth surface?
Cohesion
Water molecules are drawn together due to their strong hydrogen bonds.
What is adhesion?
The attraction between molecules of different substances
This property is observed when water interacts with glass.
What effect explains why the surface of water in a graduated cylinder dips in the center?
Adhesion between water and glass
This occurs because the adhesion is stronger than cohesion in this case.
What is capillary action?
The ability of water to rise in a narrow tube against gravity
It is caused by adhesion and is important for drawing water in plants.
How does cohesion affect capillary action?
Cohesion holds the column of water together as it rises
This is crucial for the movement of water in plants.
What is heat capacity?
The amount of energy needed to raise a substance’s temperature
Water has a relatively high heat capacity due to hydrogen bonding.
Why is water’s high heat capacity important for living organisms?
It allows large bodies of water to absorb heat with small temperature changes
This protects organisms from drastic temperature fluctuations.
Why do all living things depend on a source of water?
Chemical reactions necessary for life occur in a water environment
This is true even for organisms in the driest places on Earth.
How are cohesion and adhesion similar?
Both involve attractions between molecules
Cohesion is between the same substance, while adhesion is between different substances.
How are cohesion and adhesion different?
Cohesion is attraction between the same substance; adhesion is attraction between different substances
This distinction is important in understanding water’s behavior.
What is the significance of hydrogen bonds in water?
They give water unique characteristics, such as expanding upon freezing and dissolving many substances
Hydrogen bonds are weaker than covalent or ionic bonds but are crucial for water’s properties.
What property of water allows it to expand slightly upon freezing?
Hydrogen bonding
This property makes ice less dense than liquid water.
Define cohesion in the context of water.
The attraction between molecules of the same substance
In water, cohesion occurs because a single molecule can form multiple hydrogen bonds.
What phenomenon causes water to form beads on a smooth surface?
Cohesion
Water molecules are drawn together due to their strong hydrogen bonds.
What is adhesion?
The attraction between molecules of different substances
This property is observed when water interacts with glass.
What effect explains why the surface of water in a graduated cylinder dips in the center?
Adhesion between water and glass
This occurs because the adhesion is stronger than cohesion in this case.
What is capillary action?
The ability of water to rise in a narrow tube against gravity
It is caused by adhesion and is important for drawing water in plants.
How does cohesion affect capillary action?
Cohesion holds the column of water together as it rises
This is crucial for the movement of water in plants.
What is heat capacity?
The amount of energy needed to raise a substance’s temperature
Water has a relatively high heat capacity due to hydrogen bonding.
Why is water’s high heat capacity important for living organisms?
It allows large bodies of water to absorb heat with small temperature changes
This protects organisms from drastic temperature fluctuations.
Why do all living things depend on a source of water?
Chemical reactions necessary for life occur in a water environment
This is true even for organisms in the driest places on Earth.
How are cohesion and adhesion similar?
Both involve attractions between molecules
Cohesion is between the same substance, while adhesion is between different substances.
How are cohesion and adhesion different?
Cohesion is attraction between the same substance; adhesion is attraction between different substances
This distinction is important in understanding water’s behavior.
What are the elements of protein?
Carbon
Hydrogen
Oxygen
Nitrogen
Sometimes Sulfur
What are the elements of Fats?
Carbon
Hydrogen
Oxygen
Phosphorous
What are the elements of Carbohydrates?
Carbon
hydrogen
oxygen
What are the elements of Nucleic Acids?
Carbon
Hydrogen
Oxygen
Phosphorous
Nitrogen
Dehydration Synthesis vs Hydrolysis
DS: Removing and H and OH to allow two monomers to bond
Hydrolysis: Adding water to break apart two subunits
3 types of -acaricides
Polysaccharide
Disaccharide
Monosaccharide
4 levels of protein structure
Primary: the order of the amino acids
Secondary
Teritary
Quaternary
What is the primary protein structure
The order of amino acids
Secondary structure
Hydrogen bonds cause folding within the chain, creating ALPHA HELIXES or BETA-PLEATED SHEETS
What are tertiary and quaternary structures?
Tertiary: Complete 3D folding pattern of a single chain. A combination of sheets and helixes
Quaternary: A bunch of these chains combined.
What is pH?
The Power of Hydrogen. The more hydrogen, the more acidic. The less hydrogen, the more alkaline!
What is the difference between an organic and an inorganic molecule?
Organic molecules contain both carbon and hydrogen. Inorganic molecules may have one or the other but lack both.
The more acidic a substance is, the more ___. The more basic, the more ___.
H+, OH-
ATP is a building block of ____ because it contains ____
nucleic acid, adenine
When exposed to extreme heat, protein will be reduced to its ____ structure because…
Protein will be reduced to its primary structure, because all the hydrogen bonds will be broken down, but the peptide bonds that link amino acids together will remain intact.
True or false: enzymes are specific to their substrates.
True!
