TM Midterm

Ogliosaccharide chain

a chemical compound that is formed by a small number of simple carbohydrate molecules

transferase

class of enzymes that catalyzes the transfer of a chemical group from one molecule to another

glycosyltransferase

enzyme that catalyzes the transfer of glycosyl groups in biochemical reactions

immunodominant sugar

sugar molecule that is responsible for specificity

ABO Genes do not code for

ABO antigens

ABO genes code for

production of glycosyltransferases

what do glycosyltransferases do

catalyzes the glycosidic bonds between ABO precursor substances by adding sugars to form the full antigen

what does the bilipid bilayer on a rbc do

protects integrity, plays a role in flexibility

Where are ABO antigens found

on the surface of rbc between the bilipid layers

how do ABO antigens bind to the surface of the rbc

via ceramide molecules

what is the first precursor of ABO antigens

glucose

Where is FUT1 located

chromosome 19

what does FUT1 code for

alpha-2-L-fucosyltransferase 1

what does FUT1 do

catalyzes the addition of an L-fucose sugar to the precursor substances

what are the precursor substances on an antigen

Glucose > Galactase > N-acetylglucosamine > galactose

what percentage of the population has the H gene

99.9%

what is meant by Bombay

person is unable to make A or B antigens on the surface of their red cells

ABOs are defined by:

their immunodominant sugar

Blood group A has ___________ bound to the terminal galactose of their H antigen

N-acetylglactosamine sugar

Blood group B has ___________ bound to the terminal galactose of their H antigen

an additional galactose

what is special about blood group O and H antigens

is amorph, meaning it does not produce an a functional glycosyltransferase

Blood group AB has ___________ bound to the terminal galactose of their H antigen

both N-acetylgalactosamine sugar and an additonal galactose

FUT1 games controls for H substance, meaning that…

an additional L-fucose sugar is added to type 2 precursor substances

where are type 2 precursor substances found

bound to the membrane of the red cell

where is FUT2 found

chromosome 19

what does FUT2 code for

alpha-2-L-fucosyltransferase 2

what does FUT2 do

codes for the secretor gene (Se)

what does the secretor gene do

catalyzes type 1 precursor and creates H antigens

where is H antigen found

in secretions

H antigen is…

unbound and soluble

Secretors are found

on at least 1 of 2 alleles

what percent of the population has the secretor gene

80%

secretor gene is dominant/recessive?

dominant

the difference between Type 1 and Type 2 precursor substances is

chain linkage

Group A1 makes up what percent of the population

80%

Group A2 makes up what percent of the population

20%

what is the difference between A1 and A2

A2 transferase is less effective than A1. A2 transferase can only convert Type 1 and Type 2 H substance into A antigens, where A1 transferase can convert all types of H substance into A antigens.

a small percent of A2 patients produce…

IgM Anti-A1

A2 persons can donate to

A1

A1 persons can donate to A2 UNLESS…

they have an A antibody.

what happens if someone with an A antibody donates to an A2 person

intravascular IgM destruction

what blood group has the most H substance

O

what group has the least amount of H substance

A1B

why does A1B have the least amount of H substance

The A and B antigens compete for the available H sites, leaving little H substance left over

When are no ABO antibodies present

at birth

when do you only have the forward group (antigens) but not the reverse group (antibodies)

<4 months

When does ABO antibody production begin

3-6 months

when does ABO antibody production peak

5-10 years

what is bandeiraea simplifica

antisera that agglutinates B cells

what is Ulex europeaus

screens for Bombay but detecting the H antigen

who developed the ABO system

Karl Landsteiner

what blood group(s) are dominant

A and B

what blood groups are recessive

O

what is the law of independent segregation

genes are passed off to offspring

what is the law of independent assortment

genes are inherited differently than one another

what does it mean when DNA replication is ‘semi conservative’

during replication, an old strand joins with a newly created strand

the location of a gene is called the

locus

what is cis gene expression

2 different genes are represented on the same chromosome

what is trans gene expression

different genes are on opposing chromosomes

what is autosomal inheritance

traits are not carried on sex chromosomes

what is sex linked inheritance

traits are carried on X or Y chromosome

what is an amorph gene

a silent gene that does not produce detectable traits