Transport Flashcards
What is the average circulatory time?
1 minute
How many cells are reached in circulation?
10¹⁴ cells within minutes
How many oxygen molecules does each haemoglobin molecule bind to?
4
How many times stronger does CO bind to haemoglobin compared to O2?
250 times stronger
What percentage of CO in air leads to unconsciousness?
0.1%
What compounds have similar characteristics to CO?
CN-
H2S
What are steroids and thyroids carried through the blood by? Why?
Plasma carrier proteins
They are very non-polar and don’t dissolve in the blood plasma
What transports steroids?
Transcortin
What transports thyroid hormones?
They bind to thyroxine-binding globin
What type of core does the cell membrane have? What does this mean?
Hydrophobic
Prevents ions, charged molecules, polar molecules and peptides from passing through
What are the three ways molecules can pass through the membrane?
Passive transport
Active transport
Facilitated transport
What is passive transport?
The compound diffuses spontaneously through the membrane from high to low concentration
Does passive transport require energy?
No
What is facilitated transport?
A protein helps transport ions/molecules from high to low concentration
Does facilitated transport require energy?
No
What is active transport?
A protein pumps ions/molecules against a gradient