Cycle 3 - Lipids and Cell Membranes

What best explains why phospholipids form a bilayer in water?

The hydrophobic tails avoid water and face inward.

What specific role do glycolipids play in red blood cell membranes?

Defining ABO antigens

True or False: The membrane is a rigid, immobile structure.

False

Which feature of the cell membrane allows it to repair minor damage?

Membrane Fluidity

What would MOST LIKELY happen if glycolipids lost their carbohydrate chains?

Cell recognition processes would fail

Which combination of molecules is directly involved in cell recognition on the membrane surface?

Glycolipids and glycoproteins

What does the term 'mosaic' refer to? 

Varied and patterned arrangement of different molecules

Which property of phospholipids is critical for forming the selective barrier of the membrane?

Hydrophilic heads and hydrophobic tails

In the fluid mosaic model, what is the MAIN function of membrane proteins?

Acting as channels, carriers, and signals

Why is the cell membrane described as both “fluid” and “mosaic”?

Proteins and lipids move freely and there are many different components.

A scientist is developing a drug that must cross the cell membrane quickly without using transport proteins. Based on membrane structure, which property should the drug molecule have?

Hydrophobic and small

What structural feature of glycolipids allows them to act as molecular ID tags?

Carbohydrate chains extending into the extracellular space

Why are glycolipids critical for immune defense?

They help the immune system distinguish self from non-self.

What happens if a patient receives incompatible blood during transfusion?

Agglutination

How do glycolipids define a person’s ABO blood type?

Carbohydrate chains acting as antigens

Why is antigen matching important in organ transplantation?

It reduces the chance of rejection by the recipient’s immune system.

Which gene mutation causes Tay-Sachs disease? 

HEXA gene

What enzyme is deficient or missing in Tay-Sachs disease?

Hexosaminidase A

What is the role of hexosaminidase A in nerve cells?

Breakdown of GM2 ganglioside in nerves

What happens when GM2 ganglioside accumulates in neurons?

Progressive destruction of nerve cells

How can genetic screening help with Tay-Sachs disease?

It identifies carriers and helps families plan.

A pharmaceutical researcher wants to design a drug that can easily pass through the cell membrane without needing transport proteins. Given the membrane’s structure, what characteristic should the drug ideally have?

Hydrophobic and small

A patient needs an emergency transfusion. His blood type is B. Which donor blood types are most appropriate to avoid agglutination?

B or O

Doctors are matching an organ donor to a recipient. Why must they check glycolipid and glycoprotein markers on cell membranes?

To ensure immune recognition matches and reduce rejection

A researcher wants to reduce autoimmune reactions by modifying glycolipid structures on cells. What is the most likely goal of this approach?

Help immune cells better distinguish self from non-self

In a lab model, removing carbohydrate chains from glycolipids on red blood cells leads to what likely result?

Loss of blood type identity and possible immune attack

A genetic counselor explains to parents that they are both carriers of the HEXA gene mutation. Why is this significant for family planning?

Their children have a risk of inheriting Tay-Sachs disease.

A medical student explains why Tay-Sachs causes neuron damage. Which explanation is correct?

GM2 ganglioside builds up in lysosomes because it cannot be broken down.

During a blood shortage, hospital staff want to choose donors for a patient with type O blood. Which donor type is safest?

Type O

A pharmaceutical company is designing an artificial cell membrane for drug delivery. Why would they mimic the fluid mosaic model?

To allow flexible movement and integration of proteins and lipids

A public health nurse educates parents about newborn screening for Tay-Sachs. What is the main benefit of this screening?

It identifies affected babies early for family planning and care.