Membrane transportation and structure

Membrane transportation

Glycoproteins and glycolipids

A component plasma membrane of cells.

When do Glycoporteins and glycolipids form?

When carbohydrates are linked to other proteins or lipids.

Where are glycoproteins and glycolipids found?

Extracellular surface of the plasma membrane

Functions of Lipids

Insulation and Protection

Insulation-Function of Lipids

Fats in animals can serve as heat insulate, especially in old habitat

Protection-Function of Lipids

Triglycerides may form a tissue layer around many internal organs and provide protection against physical injury.

What is used to stabilize the membrane

Cholesterol

Phospholipid contains..

2 fatty acids and phosphate glycerol

Amphipathic

Phospholipids have both hydrophobic and hydrophillic parts

Head

Hydrophillic- water loving

Tail

Hydrophobic-water hating

Hydrophobic interactions between fatty acid tails

Hold the phospholipid bilayer together

How does fluidity change depending on the saturation of the fatty acids?

How easily the fatty acid tails move past one another.

Saturated Tails

straight sticks—packed density—hard—low fluidity

Unsaturated Tails

bent sticks— packed loosely—-soft——high fluidity

Saturated Fatty Acids

closely packed together
strong intermolecular forces
higher melting points

Unsaturated Fatty Acids

not packed neatly
intermolecular forces are weaker
lower melting points

Without the plasma membrane….

Cells of living things will die because they can’t maintain homeostasis

Semi Permeable

Membranes allow some substances to pass through easily,but not all

Molecules that can easily pass Membrane

Carbon Dioxide and Oxygen

Why can carbon dioxide and oxygen easily pass?

Non polar and small

Non polar

no charge

Molecules that cannot easily pass the membrane

Sugar,Positive Ions,Negative Ions

Polar

charged molecules

Why are  positive and negative ions not able to pass easily

Ions cannot pass through the phospholipid bilayer

Why can sugar cannot pass through the membrane easily

Large and polar

Diffussion

Membranes can only transport substances using channel proteins until there are equal amounts on both sides of the membrane.

Active Transport

Moving from high to low concentration requires the use of energy to pump substances.