Biochemistry and Cell Biology: RNA, DNA, and Cell Differentiation

What was the first biopolymer to evolve on the abiotic Earth?

RNA

What are the names of the ribonucleotides?

Adenine, Uracil, Cytosine, Guanine

How are ribonucleotides connected in RNA?

Through phosphate groups between the sugar molecules.

Which ribonucleotides base pair together in dsRNA?

G-C and A-U

How are base pairs held together in RNA?

With hydrogen bonds.

How many hydrogen bonds does G-C use?

3 hydrogen bonds.

How many hydrogen bonds does A-U use?

2 hydrogen bonds.

What can single-stranded RNA do?

Fold and form 3D structures that can perform catalysis.

What is the RNA enzyme that polymerizes amino acids into proteins?

The ribosome.

Why is RNA easily hydrolyzed in water?

Due to the action of hydroxide ions.

What has greater structural variety and performs catalysis faster, proteins or RNA?

Proteins.

Can proteins be replicated in a templated manner?

No.

Can RNA and DNA be replicated in a templated manner?

Yes.

Can DNA perform catalysis?

No.

What is the simplified central dogma of molecular biology?

Genes are stored on DNA, transcribed to mRNA, and then translated to protein.

What is LUCA?

The Last Universal Common Ancestor.

What type of organism was LUCA likely similar to?

Present day bacteria.

When did photosynthesis evolve in cyanobacteria?

2.4 billion years ago.

What event did the evolution of photosynthesis bring about?

The great oxygenation event.

What process led to the first mitochondrion in eukaryotic cells?

Endosymbiosis.

What type of cells are generally much smaller, bacterial or eukaryotic?

Bacterial cells.

What do eukaryotic cells have that bacteria generally don't?

Organelles.

What are the two types of bacteria?

Gram positive and Gram negative.

What is the structure of Gram positive bacteria?

Inner membrane bilayer and peptidoglycan cell wall.

What is the structure of Gram negative bacteria?

Inner membrane bilayer, peptidoglycan cell wall, and outer membrane bilayer.

Where is the chromosome located in bacteria?

In the cytoplasm.

What happens simultaneously in bacteria during gene expression?

Transcription and translation.

Where are chromosomes located in eukaryotes?

In the nucleus.

What happens to mRNA after transcription in eukaryotes?

Non-coding introns are cut out and the mRNA is chemically modified.

What is the difference between stem cells and terminally differentiated cells?

Stem cells can differentiate; terminally differentiated cells cannot.

What can a unipotent stem cell differentiate into?

One cell type.

What can a multipotent stem cell differentiate into?

Multiple cell types.

What can a pluripotent stem cell differentiate into?

All cell types found in adults.

What is the role of the nervous system?

To coordinate the behavior of different cell types and respond to environmental changes.

What is exteroception?

The sensing of external conditions.

What is interoception?

The sensing of internal body conditions.

What is nociception?

The sensation of pain.

What does the autonomic nervous system control?

Physiological responses not under conscious control.

What are the two parts of the autonomic nervous system?

Sympathetic and parasympathetic nervous systems.

What is the function of the sympathetic nervous system?

Fight or flight responses.

What is the function of the parasympathetic nervous system?

Rest and digest responses.

What is homeostasis?

The maintenance of stable internal conditions.

What are feedback loops?

Mechanisms that maintain homeostasis through corrective actions.

What does ATP hydrolysis release?

Energy.

What is the main source of body heat?

ATP hydrolysis.

What does the pancreas produce to regulate energy use?

Insulin and glucagon.

What is the effect of insulin?

Lowers blood glucose levels.

What is the effect of glucagon?

Raises blood glucose levels.