A&P - Proteins and Nucleic Acids Flashcards
Proteins all contain which four elements?
Carbon, hydrogen, oxygen, and nitrogen.
All proteins are made up of building blocks called _____ ______.
amino acids
Muscle tissue contains the proteins ______ and ______.
myosin and actin
Amino acids contain which two important functional groups?
The amino group (can act as a base and accept protons) and the carboxyl group (can act as an acid and donate protons).
Basic amino acid structure contains an amino group, carboxyl group, and R group. What does the R group do?
It is the variable group that makes each amino acid unique.
Proteins are formed from amino acids by _______ _______.
dehydration synthesis
Peptide bonds are ______ bonds.
covalent
Primary structure
The linear sequence of amino acids in the chain.
Secondary structure
Formed by coiling of the primary chain into an alpha helix (with hydrogen bonds maintaining the coiled structure) or a beta pleated sheet (hydrogen bonds hold primary polypeptide chains side by side in a heated structure like an accordion).
Tertiary structure
Achieved when an alpha helix or beta pleated sheet folds in a three dimensional way to produce a globular molecule. The structure is maintained by both hydrogen and covalent bonds.
Quaternary structure
Happens when two or more polypeptide chains aggregate in a regular manner to form a complex protein.
The _______ of a protein determines its function. Anything that causes the protein to unfold will result in the protein being unable to perform its job.
shape
Fibrous (structural) proteins
Most exhibit secondary structure only but some have quaternary structure as well. (collagen has quaternary structure) Examples include: collagen, keratin, actin, and myosin.
Globular (functional) proteins
Tertiary structure; some with quaternary structure as well.
Myoglobin stores ______ in muscle tissue.
oxygen
Protein denaturation
The proteins unfold and lose their biological activity.
Enzymes are _______ proteins that act as biological catalysts.
globular proteins
Enzymes work by lowering the _________ ______ of a reaction.
activation energy
Two types of nucleic acids include ___ and ___.
DNA and RNA
There are 3 major types of RNA.
messenger, transfer, and ribosomal
DNA is coiled like a spiral staircase or ladder, known as a _______ ______.
double helix
The 2 “backbones” are composed of alternating _____ and ___________ groups.
sugar and phosphate
Each “rung of the ladder is composed of 2 __________ bases hooked together by _____ bonds.
nitrogenous and hydrogen
List the 3 components of nucleotides.
N-containing base
5-carbon sugar (a pentose)
Phosphate group
Nucleoside
Consists of just a base plus a pentose sugar without the phosphate.
Purines (2 rings)
Adenine and guanine
Pyrimidines (1 ring)
Cytosine, uracil, and thymine
Complementary bases
A bonds to T (U in RNA)
G bonds to C
DNA polymerase III
Adds one nucleotide at a time to the 3’ end of the newly formed strand following base pairing rules.
RNA
produced by using DNA as a guide.
RNA polymerase
Synthesized RNA
ATP
The energy currency used by the cell.
