Cell Biology Exam 1

Mitochondrion

Organelle with both an inner and outer membrane

Oxygen

Gas that was not abundant at the time life arose on Earth

ATP production

The role of the mitochondrion

Capability of reproduction and evolution

Importance of membrane-enclosing, self-replicating RNA molecules and associated proteins

Catalysis of the polymerization of nucleotides

Why RNA was believed to be the original genetic system

Glycolysis

The first energy process during cellular evolution

B

Box with a peptide bond

Secondary structure

Results from bonds between NH and CO groups

Peptide bonds

Bonds that join the primary structure of a protein

Induced fit mechanism

Substrate binds to the enzyme and both molecules change configuration

Lysine and glutamic acid

Amino acids that would form ionic bonds

-1

Net charge of Lys-Lys-Asp-Ser-Leu-Glu-Arg-Ser

Inhibition OR stimulation

Effect of binding to an enzyme during allosteric regulation

Decreasing activation energy

How enzymes act

Ala, Trp, Leu

Amino acids found in the core away from cytoplasm

Coenzymes

Small molecules that work with an enzyme to enhance reaction rate

Proteins

Macromolecules that help package DNA in eukaryotic chromosomes

Phosphodiester bonds

Bonds that join groups of adjacent nucleotides

Antiparallel

The direction of the two DNA strands in a double helix

Purine bases

Adenine and guanine

Hydrogen

Molecule found in deoxyribose sugar

Hydroxide

Molecule found in ribose sugar

Phosphodiester linkage

5' phosphate of one nucleotide is joined to the 3' hydroxyl of the previous one

Synthesis via DNA polymerase

Adding dNTPs to a hydroxyl group on the end of a polynucleotide chain bonded to a DNA strand

DNA primers

Provide a 3' phosphate for the DNA polymerase to extend

Single-stranded DNA-binding proteins

Stabilize unwound DNA template so it can be copied by DNA polymerase

Room temperature

Is not a factor that contributes to the ease of strand separation

Okazaki fragments

Short segments of newly synthesized DNA on the lagging strand

Reverse reaction prevention

Hydrolysis of pyrophosphate (PPi) to inorganic phosphate (Pi) + Pi

Methylated nucleotides

Units that recognize the parental strand in E. coli mismatch repair

Nucleotide-excision repair

Recognizes many different lesions that distort DNA

Base-excision repair

Only recognizes and removes single damaged bases

E. coli DNA polymerase V

Recognizes thymine dimers and inserts nucleotides on the opposite strand

Recombinational repair

Repairs double-stranded breaks

Xeroderma pigmentosum

Sensitivity to sunlight that prevents nucleotide-excision repair

GTC

Sequence that results from depurination of GTAC and two rounds of DNA replication

RNA polymerase

Does not need a primer to initiate RNA synthesis

DNA polymerase

Needs a primer

TFIID

Binds to the TATA box in the first step of forming an mRNA transcription complex

Bacterial transcription

RNA polymerase and its sigma subunit initiate transcription on their own

Termination of E. coli transcription

Inverted GC-rich sequence and seven A residues

Sigma subunit

Recognizes promoter site in bacterial DNA

Transcription and DNA replication

Nucleotides are added in the 5' to 3' direction