Questions about the material

Practice Question Solving
1

-Does the animal plasma membrane consist of saturated fats ?

  • What is diffuse down the electrochemical gardient (when the chemical and voltage parts are satisfied? Both of them like in the Na and K pump where they are moved contrary to the electrochemical gradient).
  • Do I need to know the Chargaffs rule? To calculate atgc
  • There are 2 replication forks in a bubble or just one?
  • Page 376 in the book Next to the upper origin of replication the DNA polymerase would function. It will add the nucleotides after removing the primer by adding them to the 3’ end of the 1st Okazaki fragment? Will the ligase seal those after: the 3’ end of the Okazaki fragment and 5’ end of the start of the leading strand?
  • The telomeres are usually at the very very end of the linear structures? Or there are a bunch of them in every replication bubble?
  • The centrioles are not essential to the mitosis, if we destroy them, nothing changes. The mitotic spindle consists of the centrosome, the microtubules that elongate from hem and the asters. What is the role of centrioles then? And could we please talk about the 9 triplets in the centrosomes at this point when I reviewed the mitosis?
  • Could we talk about the division of the cell as a whole? How it is connected to telomeres sequences etc.
2

The plasma membrane of animal cells is primarily composed of phospholipids, which consist of a glycerol backbone, two fatty acid chains (saturated or unsaturated), and a phosphate group. While there are some saturated fats, the presence of unsaturated fats in the fatty acid chains helps maintain fluidity in the membrane.

When a substance diffuses down its electrochemical gradient, it moves from an area of high concentration to an area of lower concentration based on both the concentration gradient and the electrical potential difference across the membrane. In the case of the Na+/K+ pump, it actively moves ions against their electrochemical gradient, which requires energy from ATP hydrolysis.

Chargaff’s rules describe the ratios of nucleotide bases in DNA, stating that the amount of adenine (A) is equal to thymine (T) and the amount of guanine (G) is equal to cytosine (C). This knowledge is helpful for understanding base-pairing during DNA replication, transcription, and other processes, but it’s not necessary for calculating the ATGC composition of a DNA sequence.

There are two replication forks in a replication bubble. The replication bubble forms when DNA helicase unwinds the double-stranded DNA, creating two replication forks that move in opposite directions as replication proceeds.

DNA polymerase functions next to the origin of replication, adding nucleotides to the 3’ end of the new strand. When it encounters a primer on an Okazaki fragment, it removes the primer and fills in the gap with nucleotides. DNA ligase then seals the gap by forming a phosphodiester bond between the 3’ end of the Okazaki fragment and the 5’ end of the next fragment or the start of the leading strand.

Telomeres are located at the very ends of linear chromosomes. They contain repetitive sequences that protect the ends of the chromosomes from degradation during DNA replication. There is only one telomere at each end of a chromosome, not multiple ones within a replication bubble.

Centrioles are cylindrical structures found in the centrosomes of animal cells. Although they are not essential for mitosis, they are involved in organizing the microtubules that form the mitotic spindle. The presence of nine triplet microtubule arrangements in centrioles is a structural feature that helps maintain the shape and stability of the centrosome during cell division.

About 8- we will discuss it in our coaching together!

Have a great weekend!

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