Microbio Final

 Define what a gene is

Segments of DNA that encode functional products,

usually proteins

What is the function of Helicase

Unwinds the DNA double helix.

What is the function of Topoisomerase

 Relieves supercoiling strain.

What is the function of Primase

 Adds RNA primer to start replication.

What is the function of DNA Polymerase III:

Synthesizes the new DNA strand.

What is the function of DNA Polymerase I

Replaces RNA primers with DNA.

What is the function of Ligase

 Joins Okazaki fragments

What are the various enzymes involved in DNA replication? 

Helicase: Unwinds the DNA double helix.

Topoisomerase: Relieves supercoiling strain.

Primase: Adds RNA primer to start replication.

DNA Polymerase III: Synthesizes the new DNA strand.

DNA Polymerase I: Replaces RNA primers with DNA.

Ligase: Joins Okazaki fragments

How is DNA replication done?

DNA replication starts with Topoisomerase and Gyrase relaxing the DNA's tightly coiled structure so it doesn't break. Then, Helicase "unzips" the double helix by breaking the hydrogen bonds between the nitrogenous bases, creating a replication fork. Because the two strands are complementary and antiparallel, each original strand acts as a template for a new one. Enzymes then match up the correct bases (A with T, and C with G) to build two identical DNA molecules, ensuring the organism's genetic instructions are perfectly copied

What is DNA?

Deoxyribonucleic acid is the molecule that carries the genetic instructions for the development, functioning, growth, and reproduction of all known organisms.

What is DNA composed of?

They are composed of smaller units of  nucleotides. The nucleotides are composed of a Phosphate group, sugar (backbone), and nitrogenous bases.

What are nucleotides composed of?

A Phosphate group, Pentose sugar (backbone), and nitrogenous bases.

Which nucleotides appear ring-like and which appear circular?

Adenine (A) & Guanine (G) double ring

Cytosine ,Thymine (T), Uracil (U) single ring

Which nucleotides bind to each other in DNA replication?

A & T and G&C 

What is/are the directions of DNA replication? 

5 prime to 3 prime

 What will the anticodon for codons corresponding to each amino acid be? 

To find the anticodon, you simply need to determine the complementary base pairs for the mRNA codon. Remember that in RNA, there is no Thymine (T); instead, Uracil (U) is used.

What is the start codon?

AUG (Methionine)

When amino acid sequences from a cell cycle control protein from a patient with 

cancer and a healthy person are aligned, the sequence from the cancer patient 

indicates one amino acid has changed from phenylalanine (Phe) to leucine (Leu)? 

Essentially, this is a genetic typo known as a missense mutation. Because the DNA code was changed by just one "letter," the body accidentally swapped a bulky amino acid (Phenylalanine) for a smaller one (Leucine). Since the protein's job is to act like a "stop sign" or "gas pedal" for cell growth, this change in shape can break the protein. If the protein can no longer do its job, the cell starts dividing out of control, which is how cancer begins.

What is replication

 Making an exact copy of all the DNA in a cell

What is transcription

Copying just one specific "recipe" (a gene) from the DNA onto a smaller molecule called mRNA.

Why is transcription done

This is done because the original DNA is too big and important to leave the safety of the nucleus

What is translation

Using the mRNA "recipe" to actually build a protein. A ribosome reads the code and strings together amino acids to create the final product.

DNA Replication

DNA to DNA

transcription

DNA to RNA

Translation

RNA to protein

Which metabolic pathway(s) are NADH generated?

 NADH is produced during Glycolysis and the Krebs Cycle. In these pathways, glucose is broken down to harvest high-energy electrons, which are then used by the cell to create ATP. It serves as the primary "energy carrier" for the mitochondria.

Which metabolic pathway(s) are 

NADPH generated?

NADPH is primarily made in the Pentose Phosphate Pathway and during the Light Reactions of Photosynthesis. Unlike NADH, which is used to make energy, NADPH provides the "building power" needed for creating fatty acids and other complex molecules.

Which metabolic pathway(s) are NADH and FADH2 generated?

 

Both NADH and FADH2 are produced together during the Krebs Cycle. These two molecules work as a team to carry electrons into the Electron Transport Chain, where they power the majority of a cell's energy production.

 What is glycolysis?

The metabolic process that breaks down one molecule of glucose into two smaller molecules to release energy.

What is the final product of glycolysis?

Two molecules of pyruvate, along with a small amount of ATP and NADH.

Which pathway does  glycolysis enter into?  After glycolysis, the pyruvate usually enters the Krebs Cycle (Citric Acid Cycle) inside the mitochondria to continue the energy-making process.

  After glycolysis, the pyruvate usually enters the Krebs Cycle (Citric Acid Cycle) inside the mitochondria to continue the energy-making process.

What substrate starts the TCA cycle?

Acetyl-CoA.

What is Lithotrophy

is a type of metabolism where organisms obtain energy by consuming inorganic molecules (like minerals or gases) instead of organic matter like sugar or fats. These organisms "eat" rocks or chemicals to get the electrons they need to power their cells.

Examples of Lithotrophy

Hydrogen Bacteria: These use hydrogen gas as their energy source.

Sulfur-Oxidizing Bacteria: Often found near deep-sea vents, they use hydrogen sulfide or elemental sulfur.

Nitrifying Bacteria: Common in soil, they turn ammonia into nitrites or nitrates, which is a vital part of the nitrogen cycle.

Iron-Oxidizing Bacteria: These "eat" ferrous iron , often creating orange, rusty-colored deposits in water.

Photoautotrophs

These use light for energy and carbon dioxide for carbon.

Photoheterotrophs

These use light for energy but must consume organic compounds (like carbohydrates or alcohols) for their carbon.

Chemoautotrophs

These get energy from inorganic chemicals (like ammonia or sulfur) and use as their carbon source.

Chemoheterotrophs

These get both their energy and their carbon from organic molecules

What are the importance of nitrogen, phosphorus and carbon in the environment? 

Carbon serves as the primary building block for all organic molecules and helps regulate the Earth's temperature through the carbon cycle. Nitrogen is indispensable for creating the proteins and DNA that allow organisms to grow, though it relies on specialized soil bacteria to become usable. Finally, Phosphorus provides the structural backbone for DNA and is a core component of ATP, the molecule that powers every cellular action. Together, these elements cycle between the air, water, and soil to ensure that ecosystems remain productive and healthy.

What is Nitrification

An aerobic process (requires oxygen) where specialized soil bacteria convert ammonia (NH3) into nitrites (NO2) and then into nitrates (NO3).

What is Denitrification?

An anaerobic process (occurs without oxygen) where bacteria convert nitrates (NO2) back into nitrogen gas (N2). 

Mutualism

Both Benefit, bee and flower

Commensalism

One benefits, the other is unaffected, Remora fish and sharks

Parasitism

One benefits and one is harmed, tick and mammal

Which elements are included in biogeochemical cycle? 

Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur