Unit 1 Flashcards
Catalyst
A substance that speeds up the rate of a chemical reaction.
Enzyme
Protein that acts as a biological catalyst.
Active site
The area of an enzyme where the catalysed reaction occurs.
Substrate
The specific substance that an enzyme acts upon.
Denatured
loss of an enzyme’s normal shape so that it no longer functions; caused by a less than optimal pH and temperature.
Competitive Inhibitor
An enzyme inhibitor that competes with substrate for binding at the active site of the enzyme. Success depends on concentration.
Noncompetitive Inhibitor
A substance that reduces the activity of an enzyme by binding to a location remote from the active site, changing its conformation so that it no longer binds to the substrate.
Co-enzyme
A chemical that works with an enzyme (e.g. NAD).
Peptide Bonds
The bonds connecting amino acids together to form polypeptide chains.
Primary structure of a protein refers to
the number and sequence of amino acids held together by peptide bonds in a polypeptide chain
Secondary Structure of protein refers to
The coiled shape the polypeptide chain forms as a result of weak hydrogen bonds between certain amino acids
Tertiary Structure of a protein refers to
The shape of the coiled polypeptide chain forms when further bonding causes it to fold or twist
Striated Muscle
A muscle that appears banded; also called skeletal muscle.
Actin
Thin filament in muscle.
Myosin
Thick filament in muscle.
Sliding Filament Theory
Theory which says that the myofilaments do not become any shorter during contraction and instead slide over each other.
DNA stands for
Deoxyribonucleic acid.
Nucleotides are
Basic units of DNA molecule, composed of deoxyribose sugar, a phosphate, and one of 4 DNA bases.
Sugar-phosphate Backbone
The alternating chain of sugar and phosphate to which the DNA and RNA bases are attached.
Hydrogen Bonds
Weak chemical bonds that hold nucelotides together.
Nucleotide Pairing
Principle that bonds in DNA can form only between adenine and thymine and between guanine and cytosine.
Double Helix
Two strands of nucleotides wound about each other; structure of DNA.
RNA
Ribonucleic acid.
RNA Nucleotide
Ribose sugar, one of 4 RNA bases and a phosphate.§
Base A is
Adenine
Base T is
Thymine
Base U is
Uracil
Base C is
Cytosine
Base G is
Guanine
mRNA is
Messenger ribonucleic acid.
Codon
Three-nucleotide sequence on mRNA that codes for a single amino acid.
tRNA is
Transfer ribonucleic acid.
Anti- Codon
Group of three bases on a tRNA molecule that are complementary to an mRNA codon.
The Nucleolus controls the
synthesis of RNA and other components needed to build ribosomes
Ribosome acts as site where
tRNA and mRNA meet protein is synthesized.
Protein always contains what four elements
Carbon, hydrogen, oxygen, nitrogen.
In addition to the CHON elements what other element does protein often contain
Sulphur
RER stand for?
Rough Endoplasmic Reticulum.
Rough Endoplasmic Reticulum
Provides a large surface area for chemical reactions to occur upon and a pathway for the the transport of materials.
Golgi Apparatus
Processes and packages complex molecules ready for discharge from the cell.
Golgi Vesicle
Carries complex molecules to plasm membrane for discharge.
The RER is located close to the nucelus so that the mRNA
doesn’t have to travel far to reach it.