Category: Uncategorized

Recall that energy from passing high-energy electrons down the “steps” of the electron transport chain is harnessed to move protons (via active transport) into the mitochondrial intermembrane space. How does this help the mitochondrion to produce energy?

A solution of lemon juice has a pH of 2 and milk has a pH of 6.  The hydrogen ion concentration of lemon juice is  ______ than the hydrogen ion concentration of milk.

During which phase do homologous chromosomes separate?

You are analyzing DNA to determine which suspect was at a crime scene with a victim. You have PCR amplified short tandem repeats (STRs) from the samples and separated them via gel electrophoresis to perform “DNA fingerprinting” as follows. DNA sources are noted above each lane: Victim (Lane 1), Suspect 1 (Lane 2), Suspect 2 (Lane 3), and Crime Scene (Lane 4). DNA was loaded into wells at the top of the gel, near the lane-labels  (i.e. “Victim”, etc.).  Question:  Some of your bands in lab looked brighter than others; similarly, some bands in this gel are thicker than others. If one band looks thicker (or brighter) than another, what does this tell us about this thicker band, i.e., why is it thicker? A sentence or two should suffice.

Which of the following processes produces the most ATP?

Background: In lab, students are studying growth of radishes (a fast-growing plant).   Question: Which of the following is an example of a hypothesis related to their work?

Regulation of gene expression involves ______.

A teratoma is a tumor composed of several different types of tissue that can include muscle, teeth, hair, or bone. Teratomas develop from germ cells, a type of cell that gives rise to gametes. Because germ cells are not differentiated into specific cell types (as are e.g. muscle cells, skin cells, fat cells, etc.), teratomas can develop exhibiting numerous different cell types, giving them their name teratoma, Greek for “monstrous tumor”. Teratomas may be benign or cancerous. As a result of mistakes in processes of cell division, they are generally diploid, and sometimes polyploid. Consider a cell of a teratoma and a healthy human epithelial (skin) cell. Now consider the DNA and the three types of RNA (mRNA, tRNA, and rRNA) found in both. For each of these (DNA, mRNA, tRNA, and rRNA), compare what you would expect to find in both a teratoma and a healthy cell. Would they be the same, or different, or both? Please explain briefly but clearly for each of these four nucleic acids and provide examples or reasons. 1) DNA 2) mRNA 3) tRNA 4) rRNA Photo credits: https://emedicine.medscape.com/article/281850-overview (left) and Ed Uthman, MD. http://web2.airmail.net/uthman/specimens/index.html (right)

During which part of the cell cycle is DNA polymerase most active?

In E. coli, the lac operon should be fully expressed (turned on) ______.