1.3 The Carbon Chemistry of Life Flashcards
Carbon forms the ______ of large diverse molecules
backbone
Carbon atoms _____ to each other to form long chains, rings, or branched structures.
bind
Molecules consisting only of carbon atoms bonded to hydrogen atoms are called
_____________.
hydrocarbons
What is the smallest hydrocarbon?
Methane
The chain of carbon atoms in a biochemical molecule is the carbon _______ of the
molecule.
skeleton
Many carbon-containing rings can join to produce ________, such as the string of sugar molecules that make up a ________ sugar chain.
polymers; complex
Double or triple bonds can form between two carbon atoms, _________ the number of remaining ___________ sites by one or two,
decreasing; bonding
True or false:
There is almost no limit to the number of different hydrocarbon structures that are pos-
sible, but they are rarely used by living organisms.
True
These molecules fall into four major groups, based on their _________: carbohydrates, lipids
(fats), proteins, and nucleic acids.
function
Functional group definition
a group of atoms that affects the function of a molecule by participating in chemical reactions
Unlike non-polar hydrocarbon chains,
functional groups are usually _______ or strongly _______.
ionic; polar
Functional groups on large molecules interact with other molecules and introduce different types of _________.
bonding
the chemical or physical properties of a large biological molecule are influenced by the
______ and ______ characteristics of its functional groups.
polar; ionic
The forces of attraction that are created by ionic and polar groups are necessary in a chemical reaction in order to form new ______.
bonds
What does ethane’s high solubility mean for a cell?
It means that it can be dissolved in the cell cytosol, where it can be used as a fuel,
providing energy for the cell.
The release of H+ in water makes the carboxyl group a(n) ____.
acid
Proteins are made of ______ ____
amino acids
The amino group, NH2, can attract and bond to an H+ proton to become an _____ group.
NH3+
True or false
An amino acid has only an acid (carboxyl) as a functional group.
False
An amino acid has BOTH an acid (carboxyl) and a
base (amino) as functional groups.
Phosphate functional groups are ________
acidic
Why is the overall charge of DNA negative?
DNA is an acid because it contains a huge number of phosphate groups along the
backbone of its structure.
These groups lose their H+ ions and become negatively charged. For this reason, the overall charge of DNA is negative.
Dehydration Reaction
Removes components of a water molecule, usually during the assembly of a larger molecule from smaller subunits
An example of a dehydration reaction occurs when individual sugar molecules combine to form a _____ molecule, which is a larger
_____________
starch; macromolecule
The reverse process of dehydration is ________.
hydrolysis
What happens during hydrolysis?
In this process, the components of a water molecule, H+ and OH-, are added to functional groups as the molecules break into smaller subunits.
Which type of reaction allows the breakdown of starch into individual sugars?
Hydrolysis
True or false:
Both the assembly and breakdown of large biological molecules depend on hydrolysis and dehydration reactions.
True
During a ________ reaction, larger molecules react with water and break down into smaller subunits.
hydrolysis
Explain how the electron arrangement in carbon atoms enables them to form straight and branching chains and ring structures.
Carbon has four unpaired valence electrons allowing it to form four covalent bonds.
Carbon can bond with one or two other carbons to form straight chains.
When carbon bonds with three or four other carbons, each secondary carbon can form a chain resulting in a branched chain.
Due to electron repulsion, the bonds form a tetrahedral structure.
The angles between the bonds allow chains of carbon to bend around and form ring structures.
What is the primary purpose of the functional groups that are found in organic molecules?
Functional groups are specific groups of atoms within organic molecules that are responsible for the characteristic chemical reactions of those molecules.
The same functional group will undergo the same or similar chemical reaction(s) regardless of the size of the molecule it is a part of.
Considering the functional groups you have studied, why do you think that compounds with similar structures often have similar uses?
Compounds with similar structures often have similar uses.
Their use is dependent on the properties of the compounds and the properties are dependent on structures of the compounds.
Explain how functional groups influence solubility and the forces of attraction between molecules.
Functional groups help determine if a molecule is polar or non-polar.
This property determines the types of solvents and molecules that it is attracted to.
For example, polar solvents dissolve polar and ionic compounds and non-polar solvents dissolve non-polar compounds
What role does oxygen play in most functional groups?
In many functional groups, oxygen helps establish the polarity of the molecule.
In some groups, oxygen acts as a reducing agent by losing electrons from compounds while in other groups, it acts as an oxidizing agent by gaining electrons to form a bond.
Compare and contrast dehydration synthesis and hydrolysis.
Dehydration synthesis and hydrolysis are both processes that rearrange molecules in organic substances.
Dehydration synthesis connects smaller molecules to form larger organic compounds. Water is lost during the process.
In hydrolysis, water is added, and larger compounds are broken down into smaller units.
When would a cell use the dehydration and hydrolysis reactions of polysaccharides?
Dehydration could be used to form longer and more complex polysaccharides for cell function.
Hydrolysis could be used to reduce polysaccharides into simple more easily utilized sugars.
How will amino groups influence the solubility and or acidity of the molecule?
Amino groups decrease the acidity and increase the solubility of the molecule in polar solvents.
How will carboxyl groups influence the solubility and/or acidity of the molecule?
Carboxyl groups increase the acidity and solubility of the molecule in polar solvents.
How will phosphate groups influence the solubility and/or acidity of the molecule?
Phosphate groups increase the acidity and solubility of the molecule in polar solvents.
How will carbonyl groups influence the solubility and/or acidity of the molecule?
Carbonyl groups increase the acidity of neighbouring functional groups and increase the solubility of the molecule in polar solvents.
How will hydroxyl groups influence the solubility and/or acidity of the molecule?
The hydroxyl group does not influence acidity, but it does enhance water solubility.
Carbon molecules that
only contain Carbon and
Hydrogen are called…
hydrocarbons
true or false:
carbon molecules can occur only in unbranched chains
false
Carbon molecules can
occur in BRANCHED and
UNBRANCHED Chains
functional group
a group of atoms that
affects the function of a molecule by participating in chemical reactions
True or false:
the non-polar parts of a functional group do NOT interact in rxns
true
purpose of functional groups
makes molecules available for cell use by making them water soluble
e.g Ethanol can be metabolised by the cell because it contains a functional group that makes it water soluble.
Ethane, even though it contains more energy, is not usable since it is not water soluble due to the lack of a functional group.
Why are DNA molecules negative?
they contain phosphate groups
