BIO 202 Ch. 18 Part 2: Erythrocytes
Erythrocytes - ANS red blood cells
1. to pick up oxygen from the lungs and deliver it to tissues elsewhere
2. to pick up carbon dioxide from the tissues and unload it in the lungs - ANS 2
principal functions of erythrocytes
RBCs - ANS the most abundant formed element of blood
RBCs- severe deficiency can be fatal within minutes bc carry oxygen
deficiency of leukocytes/ platelets fatal within a few days - ANS which formed
element is most critical to survival
biconcave shape- thick rim and thin sunken center
about 7.5 µm diameter and 2.0 µm thick at rim - ANS what do erythrocytes look
like?
RBCs lose nucleus and other organelles during maturation- devoid of internal
structure - ANS what organelles are contained in RBCs?
RBCs have no mitochondria -> rely on anaerobic fermentation
no aerobic respiration means RBCs do not consume the oxygen they transport to
other tissues (deliver O2, don't consume it) - ANS how do RBCs produce ATP?
why is this significant
RBCs (deliver O2, don't consume it) - ANS what are the only human cells that
carry on anaerobic fermentation indefinitely?
hemoglobin - ANS red pigment that gives an RBC its color and name
known especially for its role in oxygen transport, but it also aids in the transport
of carbon dioxide and the buffering of blood pH
33% of cytoplasm of an RBC
, carbonic anhydrase (CAH) - ANS enzyme in the cytoplasm of an RBC that
catalyzes the reaction:
CO2 + H2O <-> H2CO3
plays a role in gas transport and pH balance
glycolipids on the outer surface - ANS what component of the plasma membrane
of an RBC determines a person's blood type?
spectrin and actin - ANS 2 cytoskeletal proteins on the inner surface of the RBC
plasma membrane that gives the membrane resilience and durability
when RBCs pass through small blood capillaries and sinusoids, many of these
passages are narrower than the diameter of an RBC, forcing RBCs to stretch,
bend, and fold as they squeeze through
when they enter larger vessels, RBCs spring back to their discoidal shape like an
air filled tube - ANS why are spectrin and actin important?
- maximizes ratio of cell surface area to volume -> quick diffusion of oxygen to all
hemoglobin in the cell
-- however, RBCs only load oxygen in capillaries and RBCs are compressed into
ovoid/ teardrop shapes when squeezing through capillaries; spring back to
biconcave when reentering larger blood vessels, but do not pick up O2
- biconcave shape minimizes RBC spin and turbulence, enabling dense slurry of
RBCs to flow through the larger blood vessels with a smooth laminar flow
- easiest, most stable shape for the cell and its cytoskeleton to relax into when
the nucleus is removed, and it may have no physiological function at all - ANS 2
possible functional advantages of the biconcave shape of the RBC
globins - ANS hemoglobin consists of these 4 protein chains (2 alpha, 2 beta)
alpha: 141 amino acids long
beta: 146 amino acids long - ANS how long are alpha globin chains?
How long are beta globin chains?
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller LECTFELICITY. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $11.99. You're not tied to anything after your purchase.
