Cells Flashcards
Defintion of a cell
A small, membrane-enclosed unit filled with a concentrated aqueus solution of chemicals. Must be able to reproduce itself.
What separates prokaryotic cells from eukaryotic?
Prokaryotic cells are without a nucleus
Which domains contain prokaryotic organisms?
Bacteria and archaea
What kind of shape does the Streptococcus bacteria have?
Spherical cells
What kind of shape does E. coli have?
Rod-like (along with Salmonella)
Name a species of spherical-shaped bacteria
Treponema pallidum
How big is a bacteria cell?
Usually a few micrometers, but can be upto 100 bigger.
Are prokaryotic cells aerobic or anaerobic?
They can be either. Aerobic cells use oxygen to oxidize food molecules, while anaerobic organisms die from exposure to oxygen.
Where do prokaryotic cells that live in inorganic environments get their energy from?
Some can perform photosynthesis in the samw way as plant cells, others derive energy from from the chemical reactivity of inorganic substances in the environment.
What are some examples of single-celled eukaryotic organisms?
Amoebae, yeast
What is th cell membrane composed of? What is the cell membranes main task?
A double layer of phospholipids. Keep things in ther place and control trasport to and from th cell.
What is cytosol?
A concentraed aqueous gel of large and small molecules. The cytosol is what fills the space between the organelles.
Where are ribosomes located?
Within the cytosol or bound to the endoplasmatic reticulum
Where is the ER located in the cell?
The ER is a membraneous system in a maze-like structure. It runs through a large part of the cell, but is particulary close to the nucleus.
How does the ER, the Golgi apparatus and lysosomes interact?
They continuosly exchange materials by way of transport vesicles that pinch off from one organelle and fuse with another.
What are peroxisomes?
Peroxisomes are vesicles used to inactivate toxic molecules by the use of hydrogen peroxide
What does the cell membrane consist of?
A double layer of phospholipids, various membrane proteins, cholesterol and carbohydrates
How does the structure of double-layer organelle membranes differentiate from the cell membrane?
They are quite similar; the biggest difference are the types of proteins used
Is the cell membrane permeable?
It is semipermeable. Most cell membranes are permeable to water.
Cytosol takes up approximately what amount of the total cell volume?
Ca. 50%
What are ribosomes made up of?
rRNA and proteins
What part of protein synthesis takes place in the ribosomes?
They recieve mRNA, decode its message and produce proteins
Where are ribosomes located in the cell?
Either free in the cytosol, or attached to the ER
What is the function of smooth and “rough”(?) ER?
Smooth ER produces lipids and stores Ca2+. Rough ER has ribosomes attached to the membrane. The ER recieves proteins directly from the ribosome, sorts them and encases them in vesicles, and sends them to the GA for further s
ortage
What is the main task of the Golgi apparatus?
It sorts through proteins recieved from ER and sends them to the proper places
