Module 1.2: Basic Chemistry of Life II Flashcards
Lipids are unique
among the biomacromolecules because most of them are insoluble in water.
Fatty acids are composed of
A zigzag line of long non-polar hydrocarbon chains
Triglycerides are the most
abundant lipids in living organisms.
After eating, triglycerides are stored within
adipocytes (fat cells).
Phospholipids contain two main components:
(1) a polar head group joined to (2) a non-polar tail group
phospholipids are considered to be
amphipathic as amphi- means ‘of both kinds’.
The head group is composed of
a charged phosphate group and (usually) a nitrogen-containing group.
The head is attracted to polar substances, such as water, and therefore is
hydrophilic (water loving).
The tail group
is a hydrocarbon
- a molecule containing an H and C—
composed of non-polar fatty acid chains.
The tail repels water and is therefore
hydrophobic (water fearing).
Steroids are
a type of lipid
made up of four, fused carbon rings
attached functional groups, often containing an alcohol (-OH) group.
Cholesterol is an
essential structural component of animal cell membranes
when found in excess, cholesterol in the blood forms plaque on artery walls, leading to an increased risk of heart attack.
Proteins are constructed from
monomers called amino acids.
Amino acids are
organic compounds
building blocks of protein.
Proteins also form enzymes
What is an enzyme?
(catalysts that speed up chemical reactions)
Proteins are used to make needed substances such as
hemoglobin, which carries oxygen in red blood cells.
What are essential amino acids?
Amino acids that must be obtained from foods in the diet
non-essential amino acids can
be manufactured by the human body.
Phenylketonuria (PKU)
Inherited condition, error in gene that codes the enzyme Phenylalanine hydroxylase
Without this enzyme, essential amino acid phenylalanine cannot be broken down, builds up in blood- can result in death
Treated with a diet low phenylalanine (essential amino acid)
Peptide bonds are
covalent bonds that hold amino acids together to form proteins.
Polypeptide
A long chain of amino acids linked together by peptide bonds
Primary structure
Specific sequence of amino acid monomers in a linear polypeptide chain
Secondary structure
- two repeating patterns that may occur in a polypeptide chain
Some regions/patterns can form 1) spring-like coil
2) while regions/payterns can form a sheet-like structure.
α-helix is
a spring-like coil configuration that comprises the basic structural unit of some fibrous proteins that make up wool, hair, skin, and fingernails.
Collagen
an important protein in skin, tendons and ligaments, provides elasticity and strength because of its triple helix structure.
ß-sheet is formed
when a polypeptide chain snakes back and forth alongside itself, making a pleated sheet that is strong and flexible, but not elastic.
hydrogen bonding occurs
between the hydrogen atom of the NH group and the oxygen atom of the C=O bond in order to hold the configuration in place
A single polypeptide chain may include both
α-helix regions and ß-sheet regions.
Tertiary structure
This is the overall three-dimensional shape assumed by each individual polypeptide chain.
Quaternary structure
Formation occurs when two or more polypeptide chains interact (to make a protein)
Hemoglobin is an example
of a globular protein composed of four polypeptide chains.
Nucleic Acids
Have chemical molecules that carry genetic information within the cell.
There are two major types of nucleic acids:
DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)
Nucleic acids are
polymers built from monomers called nucleotides.
Each DNA nucleotide may contain one of four different nitrogenous bases:
adenine (A),
thymine (T)
cytosine (C)
guanine (G)
All Tigers Can Growl
Each RNA nucleotide may also contain one of four different bases:
adenine (A)
uracil (U)
cytosine (C)
guanine (G)
All Unicorns Can Growl
**uracil **is the difference from DNA nucleotide
Why is hydrogen bonding important?
In proteins hydrogen bonds make a-helix & b-sheet regions
