1. Which structure in the cell contains the cell’s genetic information?
The nucleus of a cell contains the cell's genetic information and is also responsible
for cell division (McCance & Whether, 2014). During an acute myocardial
infarction (MI), ischemia occurs causing damage to the area of the heart muscle
not receiving oxygen. If blood flow is not restored the cells in the heart,
cardiomyocytes, become damaged. With continued hypoxia, the entire cell
becomes swollen, due to reduced ATP levels causing the plasma membrane to fail.
Plasma membrane failure allows excess chloride, sodium, and water to enter the
cell. However, these disruptions are reversible if oxygen is restored (McCance &
Whether, 2014). Damaged cells in the heart cannot be repaired so cell damage is
irreversible, but if blood flow is restored quickly after a heart attack it is possible
that the function of the heart muscle can be restored. Because of this, it is
important to have an in-depth understanding of the factors during an MI that
determine the balance between cardiomyocyte survival and death.
2. What is the process of cellular autodigestion? Which structure plays a key role
in this process?
When cells complete their life span and die, lysosomes digest the remaining
cellular debris. This process is called autodigestion and the lysosomes involved in
this process are termed autolysosomes or autophagosomes. In the case of living
cells, that cellular debris gets encapsulated in a vesicle which reacts with a
lysosome to end its degradation.
3. Name the 4 phases of the cell cycle and the important steps in each phase.
Interphase (G1, S, and G2 phases) are the longest phase of the cell cycle. During
interphase the chromatin consists of very long, slender rods that are jumbled
together in the nucleus. Late in interphase, strands of chromatin being to coil,
causing them to shorten and fatten.
The M phase of the cell cycle, mitosis and cytokinesis, begin with prophase, the
first appearance of the chromosomes. As the phase proceeds, each chromosome is
seen as two identical halves (sisters) called chromatids, which lie together and are
attached by a centromere.
The (sisters) are genetically identical. The nuclear membrane disappears. Spindle
, fibers are microtubules formed in the cytoplasm. The role of the spindle fibers is
to pull the chromosomes to opposites sides of the cell.
During metaphase, the next phase of mitosis and cytokinesis, the spindle fibers pull
the centromerers of the chromosome. The centromeres become aligned in the
middle of the spindle (metaphase plate) of the cell. During this phase,
chromosomes are easiest to observe
microscopically because they are highly condensed and arranged organized in a
two-dimensional plate.
Anaphase begins when the centromeres split and the sister chromatids are pulled
apart. The spindle fibers shorten causing the sister chromatids to be pulled towards
opposites ends of the cell. When the sister chromatids are separated, each is
considered a chromosome.
The cell has 92 chromosomes during this stage. By the end of the anaphase, 46
chromosomes is identical to the original 46 chromosomes present at the start of the
cell cycle.
Telaphase, the final stage, a new nuclear membrane is formed around each group
of 46 chromosomes, the spindle fibers disappear, and the chromosomes began to
uncoil. Cytokenesis causes cytoplasm to divide into roughly equal parts .At the end
of this phase,
two identical diploid cells (daughter cells) have been formed from the original cell.
4. What is the function of the "gap junction"?
The presence of gap junctions in the cardiac muscle facilitate cardiac function
because they synchronize contractions of the heart muscle cells through ionic
coupling. Communication is a key role in gap junction.
5. How are messages transferred through the cell?
For cells to maintain homeostasis it is vital that they communicate with other cells
within the body. Cells utilize hundreds of different signal molecules when
communicating with one another, these molecules allow cells to communicate in
three main ways. The three main ways are “(1) they display plasma membrane–
bound signaling molecules (receptors) that affect the cell itself and other cells in
direct physical contact (2) they affect receptor proteins inside the target cell and the
signal molecule has to enter the cell to bind to them (3) they form protein channels
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Smartstudies. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $20.49. You're not tied to anything after your purchase.
