bio topic 1 Flashcards
Which method provides biochemical evidence that cells have begun to differentiate?
Analysis of the proteins
How long is Scenedesmus usually?
11 to 22 micrometers long
What is the difference between eukaryotic and prokaryotic cells?
Compartmentalization is found only in eukaryotes
What would happen to onion cells if they were transferred to a hypertonic solution
Cell membranes would detach from call walls at some points
Which organelle would be found in Paramecium and not in Chlorella
Contractile vacuole
Which features can be found in phagocytic white blood cell and in a photosynthetic bacterium?
70s ribosomes
What kind of ribosomes are in mitochondria?
70s ribosomes
What both viruses and living cells have in common?
Genetic material
What is the role of glycoprotein secreted by animal cells as extracellular components?
Adhesion
What allows glucose to be transported through the blood plasma?
It’s polar features
Who concluded that the cell membrane is made up of a lipid bilayer?
Gorter and Grendel
What was the cell component that arose first during the formation of the earliest cells?
Plasma membrane
What is the main role of cholesterol in the mammalian cells?
To regulate the fluidity of the membrane
By what evidence was the Darson-Danielli model of membrane structure supported?
By the evidence from the electron micrograph that showed two dark lines and a brighter band in between
By what evidence was the Darson-Danielli model of membrane structure supported?
By the evidence from the electron micrograph that showed two dark lines and a brighter band in between
What are the functions of the membrane proteins?
Cell-to-cell communications and protein pumps
What is possible due to the fluidity of the membrane?
Endocytosis
What is the approximate thickness of the plasma membrane of the cell?
10 nanometers (nm)
What is the evidence that falsifies Darson-Dinealli cell membrane model?
- The presence of globular proteins within the phospholipid bilayer
- Non-polar amino acids cause proteins to remain embedded in membranes
The concentration of ions inside and outside human cells is maintained by the sodium-potassium pump. How does he pump work?
Active transport pumps sodium ions out and potassium ions in.
What is an isotonic solution?
Solution in which the cell functions at its normal size
What is a hypertonic solution?
Solution in which the cell shrinks and wrinkles
What is a hypotonic solution?
Solution in which the cell swells up and bursts
Which processes occur by osmosis?
- Loss of water from a plant cell in a hypertonic environment
- Evaporation of water by sweat on the skin surface
