Chapter 3 - Molecules Of Cells Flashcards
Life’s molecular diversity is based on what?
The properties of carbon
Almost all molecules a cell makes are composed of what?
Carbon bonded to:
- Other carbons
- Atoms of other elements
- most commonly bonds with H, O, and N
Carbon based molecules are called what?
Organic compounds
What is a carbon skeleton?
A chain of carbon atoms that can differ in length
What are 3 properties of carbon skeletons?
They can be:
- Straight
- Branched
- Arranged in rings
What are hydrocarbons?
Organic molecules consisting of only carbon and hydrogen
Why does CH4 not dissolve in water?
Because it is non-polar
Why is CH4 no polar?
Because the hydrogen atoms (H4) and carbon (C) share electrons equally creating non-polar covalent bonds
CH4 is commonly called _____.
Methane
What are a derivative of hydrocarbons?
Carbohydrates
Carbohydrates are composed of which elements?
C, H, O
What are the 3 classes of carbohydrates?
Monosaccharides (simple sugars)
Disaccharides (2 sugars)
Polysaccharides
What is the chemical formula for monosaccharides?
C6 H12 O6
What is the chemical structure of a disaccharide?
C12 H22 O11
Through what process are simple sugars combined?
A dehydration reaction,
Or Hydration synthesis (?)
What are isomers?
Compounds with the same chemical makeup, but different covalent arrangement of their atoms
What are geometric isomers?
They differ in arrangement around a double covalent bond (the double covalent bond remains the same)
What are structural isomers?
Different covalent arrangements
What is an Enantiomer?
Enantiomers differ in spatial arrangement around an asymmetric carbon, resulting in molecules that are mirror images
What are functional groups?
Commonly occurring groups of atoms with characteristic reactivity
What gives each molecule of a functional group it’s unique properties?
The number and arrangement of the functional groups
When is a disaccharide formed?
When a dehydration reaction joins two monosaccharides (monomers)
The covalent bond between two monosaccharides is called what?
Glycosidic linkage
What are polysaccharides?
Macromolecules, polymers of hundreds to thousands of monosaccharides linked together by dehydration reactions
What are polymers?
A long molecule consisting of many identical or similar building blocks strung together
What are monomers?
The building blocks of polymers
What is the most common disaccharide?
Sucrose
What is sucrose made of?
A glucose monomer and fructose monomer linked together
What is the function of polysaccharides?
May function as storage molecules or as structural compounds
What are three common types of polysaccharides?
Starch, glycogen, and cellulose
What is a second type of disaccharide?
Maltose
What type of saccharides does Maltose consist of?
2 glucose compounds
What is hydrolysis?
The bonds between monomers are broken by the addition of a water molecule
What is starch?
A storage polysaccharide of plant
What does starch consist of? (As a polysaccharide)
Glucose monomers
Where do plants stores excess starch?
Stored as granules within chloroplasts and other plastids
What is an example of a storage polysaccharide within humans and other vertebrate animals?
Glycogen
Where is glycogen stored in humans and other vertebrae?
In liver and muscle cells
What are 2 types of structural polysaccharides?
Cellulose
Chitin
What is cellulose?
A polymer of glucose (it forms plant cell walls)
What is Chitin? Where is it found?
A polysaccharide
Used by insects and crustaceans to build exoskeleton
Found in cell walls of fungi
What are lipids?
A diverse group of molecules that are classified together because they are hydrophobic
Lipids are not formed by ________.
Polymers
Lipids are the one class of large biological molecules to not do what?
Form polymers
What is the unifying feature of lipids?
They have little to no affinity for water
Why are lipids hydrophobic?
Because they consist mainly of hydrocarbons, which form non-polar covalent bonds
What are the 3 most biologically important lipids?
Fats
Phospholipids
Steroids
Fats are constructed from what 2 types of smaller molecules?
Glycerol and fatty acids
What is glycerol?
A 3 Carbon atoms with a hydroxyl group attached to each carbon
A hydroxyl group consists of what?
A hydrogen atom bonded to an oxygen atom
What are alcohols?
Ethanol and other organic compounds containing hydroxyl groups
How is the hydroxyl group notated?
—OH
A carbonyl group consist of what?
A carbon atom linked by a double covalent bond to an oxygen atom
How is a carbonyl group structure notated and diagrammed?
Bonus: Where can a carbonyl group be located?
\
C=O
/
H O H
| || |
—C—C—C—
| |
A carbonyl group can be located in the middle of or at the end of a carbon skeleton (chain)
Where can carbonyl groups be located?
Within or at the end of a carbon skeleton
Simple sugars contain what type of functional groups?
Both hydroxyl and carbonyl
What is the carboxyl group?
A carbon atom double bonded to an oxygen atom and bonded to a hydroxyl group
How is the carboxyl group notated and diagrammed?
—COOH
For example:
O // -C \ OH
(Carboxylic acid)
How is an ionized carboxyl group notated?
O // -C + H+ \ O-
Ionized carboxylic acid
The carboxyl group can function as an _______.
Acid
How can the carboxyl group function as an acid?
It can contribute an H+ to a solution, this becoming ionized
Compounds with carboxyl groups are called what?
Carboxylic acids
Ethanol, and other organic compounds containing a hydroxyl group are called what?
Alcohols
What is the amino group?
A nitrogen bonded to two hydrogens
How is an amino group notated?
-NH2
The amino group can function as a what?
Base
Why can the amino group function as a base?
It can pick up an H+ from a solution and become ionized
What are organic compounds with an amino group called?
Amines
What are the building blocks of proteins?
Amino acids
Amino acids are comprised of what functional groups?
An amino and carboxyl group
How is an amino group notated? (Diagram)
H / -N + H+ \ H
How is the ionized form of an amine notated (diagram)?
H
/
-(N+)—H
\
HWhat is the phosphate group?
A phosphorous atom bonded to 4 oxygen atoms
Phosphate groups are usually _______.
Ionized
The oxygen atoms in a phosphate group are ________ charged.
Negatively charged
How is a phosphate group notated?
-OPO3^(-2)
How is an adenosine tri-phosphate notated?
O O O || || || \+O—P—O—P—O—P—O(-) | | | O- O- O-
(The O+ is indicates where Adenosine is bonded)
Compounds with phosphate groups are called ______.
Organic phosphates
Organic phosphates are often involved in what activities?
Energy transfers
ATP is what?
Adenosine Triphosphate (an organic phosphate compound)
What is a property of ATP?
It is energy rich
How is a phosphate group notated?
O
||
—P—O(-)
|
O-What is a methyl group?
A carbon atom bonded to 3 hydrogen atoms
How is a methyl group notated?
—CH3
What are the 6 functional groups?
Hydroxyl group Carbonyl group Carboxyl group Amino group Phosphate group Methyl group
Are all function groups hydrophilic?
No
Which functional group(s) are hydrophobic?
Methyl group
How is glycerol notated? (Diagram)
H H H
| | |
H—C—-C—-C—H
| | |
OH OH OH
(Fatty acids bind to glycerol via dehydration synthesis with the OH molecules of glycerol attach to the carboxyl group of a hydrocarbon chain (fatty acid)
What does a fatty acid consist of?
A carboxyl group attached to a long carbon skeleton
A fatty acid is what?
A lipid
Fats are what?
Lipids
Phospholipids are what?
Lipids!
When carbon double bonds to carbon, are the bonds saturated or unsaturated?
Unsaturated
How do fatty acids differ?
- They vary in length (# of carbons)
- They vary in # and locations of double bonds
Saturated fatty acids have how many double bonds?
None
What are saturated fatty acids?
Fatty acids with the maximum number of hydrogen bonds and no double bonds
What are unsaturated fatty acids?
Fatty acids containing one or more double bonded carbons
What is the primary function of fats?
To store energy
What are two examples of saturated fats?
Butter
Steak
What are two examples of unsaturated fats?
Olive oil
Salmon
What fatty acid is in butter?
Stearic acid (no double bonds)
What fatty acid is in olive oil?
Oleic Acid (double bonds between carbon molecules exist)
The process of hydrogenation creates what?
Trans Fats
What are trans fats?
A form of fat associated with health risks.
What does “Partially Hydrogenated Oil” mean?
That unsaturated fats have been converted to saturated fats by adding hydrogen, hydrogenation
What are phospholipid?
The major component of cell membranes
How are phospholipid structurally similar to fats?
They contain 2, instead of 3, fatty acids attached to glycerol
Protein vary in what two purposes?
Function and structure
Proteins are involved in what?
Nearly every dynamic function in your body
Proteins are ____.
Diverse
How many different proteins?
Tens of thousands, each with its own particular structure and function
What are proteins made of?
One or more long chains of amino acids or polypeptides
What are poly peptides?
Polymer
What is an amino acid?
Monomer
How many amino acids are there?
20
How many functional groups exist for amino acids?
3
What are the 3 functional groups of an amino acids?
Amino group
Carboxyl group
“R” group
What is the “R” group?
Consists of one or more carbon atoms with various functional groups attached
What is the “R” group in the simplest amino acid, glycine?
A hydrogen atom
How are amino acids linked together to form polymers?
Cells join amino acids together in a dehydration reaction
The dehydration reaction linking amino acids together does what?
Links the carboxyl group of one amino acid to the amino group of the next amino acid as a water molecule is removed.
What is a peptide bond?
The covalent linkage between amino acids as a result of a dehydration reaction causing linkage between the carboxyl and amino groups of separate amino acids
What is a dipeptide?
Two amino acids bonded together via peptide bond
What is a polypeptide?
A group in 3 or more amino acids bonded together via dehydration reaction
How long are most polypeptides?
100s, some 1,000s, of amino acids in length
What is the primary structure of a protein?
The precise sequence of amino acids in the polypeptide chain
How many physical categories of amino acids are there?
3
What are the physical categories of amino acids? How many amino acids in each group?
- Hydrophilic (9)
- Uncharged, polar (6)
- Charged polar (5)
What are the hydrophilic amino acids?
Glycine, alanine, valine, leucine, isoleucine, methionine, proline, phenylalanine, tryptophan
What are the uncharged polar amino acids?
Serine, threonine, asparagine, glutamine, tyrosine, cysteine
What are the charges polar amino acids?
Lysine, arginine, glutamic acid, aspartic acid, and histidine
How many levels of protein structure are there and what are they?
4
Primary structure
Secondary structure
Tertiary structure
Quaternary structure
What are the types of secondary protein structures?
Alpha helix
Beta pleated sheet
What is the secondary structure of a protein?
When segments of the polypeptide chain coil or fold into local patterns
What is the tertiary structure of a protein?
The overall three dimensional shape of a protein
What are quaternary structures?
Proteins consisting of more than one polypeptide chain
What determines protein conformity?
Primary structure, physical and chemical conditions affect protein structure
What can cause a protein to unravel?
Alterations in pH, salt concentration, and temperature
What is denaturation?
The loss of a protein’s native conformation
A denatured protein is ________.
Biologically inactive
Denatured proteins can be ______.
Denatured
What are 6 functions proteins perform?
- Structural support (keratin in fingernails
- Transport (proteins associated with cellular membranes)
- Regulatory (insulin)
- Catalytic (enzymes)
- Defense (antibodies)
- Movement (muscle contractions)
What does DNA stand for?
Deoxyribonucleic Acid
What does RNA stand for?
Ribonucleic acid
Nucleus acids are made from __________.
Polymers of nucleotides
What is a nucleotide?
The monomers that make up nucleic acids
What is a polynucleotide
A polymer
What is at the center of a nucleotide?
A 5 Carbon sugar
What is the sugar in DNA?
Deoxyribose
What is the sugar in RNA?
Ribose
How do lipids differ from carbohydrates, proteins, and nucleic acids?
- lipids are not huge macromolecules
- lipids are not polymers built from single monomers
Lipids are not _______.
Macromolecules
How many parts of a nucleotide are there and what are they?
3
Center: a 5 Carbon sugar
Linked to one side of the sugar is a negatively charged phosphate group
Linked to the sugar’s other side is a nitrogenous base
What is a nitrogenous base?
A molecular structure containing nitrogen (N) and carbon (C)
How many nitrogenous bases does a DNA nucleotide have? What are they?
4
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)
All genetic information is written in a ___ letter alphabet. What are they?
4
A, T, C, G
RNA nucleotides contain which nitrogenous bases?
A, C, and G
Also
U - uracil (instead of thymine)
What are polynucleotides?
A nucleic acids polymer
Built from its monomers by dehydration reaction
How are nucleotides joined to form polynucleotides (nucleotide polymers)?
Through a dehydration reaction.
The sugar of one nucleotide (C5, of a 5 Carbon sugar) bonds to the phosphate group (OH) of the 5 Carbon of the next monomer.
What is the backbone of a polynucleotide?
Sugar-Phosphate-Sugar-Phosphate…etc
What are NOT part of the backbone of polynucleotides?
Nitrogenous Bases A, C, T (U), G
RNA consists of how many nucleotide strands?
1
DNA consists of how many nucleotide strands?
- Wrapped in a double helix
What occurs to the nitrogenous bases attached to strands of DNA nucleotides?
The nitrogenous bases protrude from the two sugar-phosphate backbones and pair in the center of the helix.
A pairs with what?
T
C pair with what?
G
How do the nitrogenous bases (DNA chains) stay together?
They are held together by hydrogen bonds
Individually, the hydrogen bonds of DNA are _______ but together they are ______.
Weak
Strong
The two nucleotide strands of DNA are complimentary. What means that?
Due to base pairing, the sequence of bases can be predicted based off of the other strand.
What structures carry DNA
Chromosomes
Each chromosome carries how many genes?
Several hundred or more
What makes DNA unique to molecules?
It provides its owns directions for replication
In animals, what do the liver and muscle cells do to glycogen stored there, when need?
Hydro luxe the glycogen to release glucose as needed.
What is the functional group that gives fatty acids their name?
—COOH
In a fatty acid, how long is the carbon chain the carboxyl group is attached to?
16-18 Carbons in length
Why are fats hydrophobic?
Because of the non-polar C—H2 bonds in the HYDROCARBON chain
What is a hydrocarbon?
A carbon chain containing carbon and hydrogen
