Chapter 3 Flashcards
What is the difference between prokaryotic and eukaryotic cells?
Prokaryotic cells do not contain membrane bound organelles. Most importantly, they do not contain a membrane bound nucleus
Why are cells so small?
They are more efficient - a large cell both requires more nutrients and has a worse surface area to volume ratio, which means that it will take longer for nutrients and other things to travel around the cell
What does cell theory state?
It states that
1) All organisms are composed of one of more cells
2) All cells come from other cells
How small can cells be?
They can be as small as 1 micrometer , but are usually between 10 and 100 micrometers
What does the cell membrane do?
It regulates the entrance and exit of molecules into and out of the cell
What are the three layers that protect bacteria cells?
The cell wall, the capsule, the plasma membrane
What is the organelle that some bacteria have that helps then attach to surfaces?
The fimbriae, which are hairlike bristles
What is the flagellum?
It is a long, rotating filament that helps the cell move
What is a prokaryotic nucleoid?
It is a single loop of chromosome that is not bound by membrane
What do ribosomes do?
They synthesize DNA
What does the cell wall do?
It is a permeable but protective layer that protects the cell
What kind of cell only contains chloroplasts?
The plant cell
What kind of cell only contains centrioles?
The animal cell
What does the nucleus do?
It stores DNA, which helps govern the cell
What is chromatin?
It is stored in DNA and unravels to form chromosomes during cell division
What does the nucleoplasm do?
It is a substance in the nucleus that chromatin is immersed in
What does the nucleolus do?
It produces rRNA (ribosomal RNA). It also provides the site for rRNA to join with proteins to form ribosomes
What is the nuclear envelope?
It is a double membrane that separates the nuclear from the rest of the cell
What are nuclear pores?
They are holes that are around 100nm that permit proteins to pass into the nucleus and ribosomes from the nucleolus to pass out
What is the advantage of a light microscope?
You can observe living cells and organisms
What is the advantage of a scanning electron microscope?
They can provide a more detailed surface view of an organism
What is the advantage of a transmitting electron microscope?
You can get a detailed view of the inside of a cell
What do ribosomes do?
They synthesize proteins
What does the Rough ER do?
It contains ribosomes that synthesize proteins. The proteins then enter the ER, where it processed and modifies and transports proteins
