A&P Practice Lecture Questions for Exam 1

Describe why water carries a partial positive and partial negative charge

Describe the process of transcription in detail

It is the process of making an mRNA copy of a DNA sequence (gene- sequence of DNA that codes for protein). The first step is initiation, the RNA polymerase (an enzyme that makes mRNA) lands on the promoter and begins to move toward the start codon. The second step is elongation, and once the start codon is reached, polymerase begins laying down complimentary nucleotides to the DNA sequence. This continues until the stop codon is reached. The third step is termination, and once the stop codon is reached, the RNA polymerase floats away and leaves a strand of mRNA.

Describe the human genome

It has about 3 billion base pairs and 50,000 genes distributed over 23 pairs of chromosomes

What are the differences between DNA and RNA?

DNA uses deoxyribose and RNA uses ribose. In DNA, A (adenine) pairs to T (thymine) but in RNA , A pairs to U.

What does mRNA, tRNA, and rRNA do?

mRNA is a copy of the gene from a DNA sequences- mRNA contains codons which are 3 nucleotides that code for an amino acid. tRNA transfers an amino acid to a growing chain of amino acids during translation and has an anticodon. rRNA composes the ribosome and the ribosome itself is made of rRNA

Describe the four levels of protein structure

The first is the primary structure which is the sequence of amino acids. The secondary structure is made from the primary, and it has alpha helices, beta sheets, and turns/coils that link them. Tertiary is the folding of 2 more secondary structures, and it is formed from covalent, ionic, and hydrophobic interactions. Quaternary, is formed from 2 or more tertiary structures and it is formed as a result of covalent, ionic, and hydrophilic interactions.

Describe delta G and how it is used in reactions

Describe the process of translation in detail

Describe the pH scale and what an acid and base are

How is water like an acid and a base?

Describe a ribosome with the sites on it

Ribosomes are composed of rRNA and are platform for translation. It has 3 sites- A, P, and E. tRNA carry an amino acid, there are 20 different AA’s, but the genetic code is redundant, meaning multiple tRNA’s carry the same AA.

How is the genetic code redundant?

It is redundant because there are multiple, distinct, three letter DNA or RNA sequences known as codons that code for the exact same amino acid.

What is the destination of proteins translated on the free floating ribosomes versus the rough endoplasmic reticulum?

The destination of proteins translated on the FFR remain the cytosol or are transported into specific intracellular organelles, while proteins translated through the RER are destined for secretion, lysosomes, or into the cell membrane.

What is the purpose of the mitochondria? How is the mitochondria unique to other organelles?

The mitochondria is responsible for 36/38 ATP per glucose. And the citric acid cycle and Electron transport chain occur in the mitochondria. It is unique because it has its own genome, 70s ribosomes, and more than 1 billion years ago, the 1st eukaryotic cell engulfed the 1st mitochondria via phagocytosis.

What is the difference between a saturated and unsaturated lipid?

Saturated lipids only have single bonds between the carbons and are saturated with as many hydrogens as possible. But unsaturated lipids have double bonds between carbons, so they do not have the maximum number of hydrogens possible and are flexible due to gaps in the electron clouds.

Explain the difference between a covalent bond and an ionic bonds. Give examples.

What is amphipathic molecule? What part of the lipid is hydrophilic, what part is hydrophobic?

What is anabolic and catabolic reaction ?

What is an ion and isotope?

What are the properties of an enzyme ?

Explain why amines carry a positive charge and carboxylic acids carry a negative charge

What does the term denature mean with proteins?

How is atomic mass calculated?

Write the electron configuration for the following

1. Carbon 6e

2. Oxygen 8e

3. Hydrogen 1e

4. Nitrogen 7e

5. Sodium 11e

6. Chlorine 17e

What is an isomer and an enantiomer?

What kind of proteins are found in the cell membrane?

There is the pump, channel, adhesion, and receptor proteins.

Explain the lipid bilayer. What parts of it are hydrophilic and hydrophobic ?

It is composed of lipids with hydrophilic heads and hydrophobic tails. The heads are charged nitrogen’s and oxygens that can associate with water. The tails are carbon and hydrogen.

What makes a molecule hydrophilic or hydrophobic?

A molecule is hydrophilic when it has a charged oxygen or nitrogen that can associate with the partial charges on water. Hydrophobic molecules are not charged.

Explain why water has a partial positive and negative charge.

Explain transcription and translation

What is an anabolic and catabolic reaction? Give examples and mention which creates or uses a water molecule.

What is the purpose of peroxisomes?