Chapter 4 - Cards 11-20: Organelles Flashcards
Which organelle has two subunits and serves as the location for protein synthesis?
The ribosome.
Study the following images. One is a macro view and one is a zoomed-in view. Seriously, how cool is this? Don’t be thinking about definitions - think about what is truly happening here! Be wonderous (this course will so much more fun that way!)
In what part of the cell is the nucleolus located, and what function does it serve? Hint: Unlike other organelles, this organelle is not membrane-bound.
The nucleolus is located within the nucleus.
One of its primary functions is to produce a molecule called ribosomal RNA. Ribosomal RNA makes up a ribosome (imagine that!). What are ribosomes? Stay tuned!
The nucleus has pores in its nuclear envelope. What is the function of these nuclear pores?
The pores are used to transfer molecules made inside the nucleus such as RNA (used for protein synthesis) and proteins and RNA building blocks from the outside of the nucleus to the inside..
Which organelle has two subunits and serves as the location for protein synthesis?
The ribosome
At these organelles, proteins are synthesized (translated). A typical ribosome includes a small and a large subunit of ribosomal RNA (r-RNA).
A lot more to come about this process. For now, it’s good enough to know just the basics.
What is the endoplasmic reticulum (ER). There are two kinds of ER, rough and smooth. What is each type used for?
The ER is a network of canals that are continuous with the nuclear membrane. The rough ER is “rough” due to the presence of ribosomes and is, therefore,
the site of protein synthesis.
The smooth ER (no ribosomes) is the site of:
lipid synthesis
carbohydrate metabolism
detoxification of poisons and drugs (eg. by adding an OH group to make them soluble in water).
What is the role of the Golgi apparatus?
The Golgi apparatus modifies molecules that arrive from the ER (delivered in vescicles) and then modifies these products and packages them for delivery to the appropriate locations intracellularly or extracellularly.
Which organelle found in animal cells may have arisen as a result of mutualism?
Mitochondria may have evolved from a symbiotic relationship between small bacteria and larger cells. This is known as the endosymbiotic theory.
Side note:
Like all instances of mutualism, this situation is thought to have provided benefits to both organisms. The smaller bacterium was given a livable environment while providing energy for the larger host.
What is the cellular role of lysosomes?
A lysosome contains digestive enzymes (pH around 4). Lysosomes:
break down excess or worn-out cell parts.
destroy invading viruses and bacteria.
If the cell is damaged beyond repair, lysosomes can help it to self-destruct in a process called programmed cell death, or apoptosis.
Potential quiz question: Why might increasing the pH of a lysosome be a cure for COVID?
What does the cytoskeleton do and what are its three parts?
Note from the attached image how entire books have been written on each of the cell’s organelles! (Yet there is still so much we don’t know)
The cytoskeleton is involved in cell movement, endocytosis (pulling material into the cell), and for moving DNA during cell division.
The three components are (we will go over these a little later)
microtubules
intermediate filaments
microfilaments
Which two membrane-bound organelles are unique to plant cells?
Plant cells, unlike animal cells, contain chloroplasts and vacuoles.
Chloroplasts resemble mitochondria and perform the reactions of photosynthesis. Vacuoles are involved in storage.
