Prokaryotic and Eukaryotic Cells, DNA Structure, and Gene Expression

Flashcards covering cell types, DNA discovery, molecular structure, replication, protein synthesis, and gene regulation based on the lecture transcript.

Prokaryotic cells typically range in size from __________ to __________.

$$100\,nm-10\,\mu m$$

In 1869, Swiss biologist Friedrich Miescher identified a cellular substance from the nucleus and named it __________.

nuclein

In Frederick Griffith's 1928 experiments, the virulent disease was caused by the __________, which is surrounded by a capsule.

smooth strain (S cells)

The process by which bacteria take in DNA from their surroundings is known as __________.

Transformation

In 1944, Oswald Avery, Colin MacLeod, and Maclyn McCarty proved that DNA was the "transforming factor" by treating S cell extract with __________, which degraded the DNA and prevented transformation.

DNases

A nucleotide is composed of a phosphate molecule, a nitrogenous base, and a 5-carbon sugar called __________.

deoxyribose

The nitrogenous base __________ is found in RNA only, replacing Thymine.

Uracil (U)

Rosalind Franklin and Maurice Wilkens provided __________ data in 1951 to show the helical structure of DNA.

x-ray crystallography

The bonds used to hold nucleotides together in a single strand of DNA are called __________ bonds.

Phosphodiester

DNA strands are described as __________ because their polarity is reversed relative to each other.

antiparallel

__________ is the state of DNA inside the nucleus when the cell is NOT dividing, consisting of DNA wrapped around histones.

Chromatin

In humans, chromosome pairs 1-22 are referred to as __________.

Autosomes

The highly conserved repetitive nucleotide sequence at the end of each chromosome arm that enables cells to divide without losing genes is the __________.

telomere

The set of all DNA in an organism's cell is called the __________.

Genome

DNA replication is __________, meaning it results in one original parental strand and one newly synthesized strand.

Semiconservative

The enzyme __________ synthesizes short segments of RNA (10-15 nucleotides long) to start the replication process.

DNA Primase

DNA Polymerase reads or scans the template strand in the __________ direction.

$3'$ to $5'$

On the lagging strand, short segments called __________ are synthesized discontinuously.

Okazaki fragments

The __________ explains that DNA codes for RNA, which then codes for proteins.

Central dogma

During transcription, RNA polymerase binds to a __________ region to begin unwinding the DNA helix.

promoter

The 3' modification added to protect mRNA from degrading enzymes and increase stability is the __________.

PolyA tail

In the genetic code, the three-nucleotide units of mRNA are called __________.

codons

The enzyme __________ catalyzes the formation of peptide bonds between two amino acids during the elongation stage of translation.

Peptidyl transferase

In the lac operon, the gene __________ codes for permease, a membrane protein that transports lactose into the cell.

lac Y

__________ are approximately 21 nucleotide double-stranded non-coding RNAs that begin in the cytoplasm and silence specific target mRNA by cleaving it.

Small (short) interfering RNA (siRNA)

Gene mutations that occur in the genome of somatic cells and are not passed to offspring are called __________.

Acquired mutations

The term __________ refers to modifications in chromatin structure, such as DNA methylation, which do not involve mutations in the DNA sequence.

Epigenome

In a Phenol/Chloroform DNA extraction, DNA partitions to the upper __________ phase.

aqueous