Biology Ch. 8 - Biological Membranes

Photosynthesis

The process of converting light into energy

Photoautotrophs

Organisms that perform photosynthesis
Ex) Plants, Algae

Integrins

Embedded in the membrane and are like long hands that stick to things and communicate

Heterotrophs

Consumes other organisms for energy
Ex) Animals, Humans

Peripheral Proteins (what do they do)

They help with structure and recognition sites, only located on the outside/inside of the membrane (never in the middle).

Carbohydrates

They are used for identification, located on the outside of proteins or lipids

Ex) They are like the fingerprints, cells look at the carbohydrate patterns

Selective Permeability

The ability to let specific things in and specific things out to keep the inside different from the outside

1. Things that move easily;

   1. Nonpolar substances

   2. Hydrophobic substances (Lipid-soluble substances)

   3. Low molecular weight

2. Things that do not move easily;

   1. Polar substances

   2. Hydrophilic substances

   3. High molecular weight

   4. Charged ions

Chemoautotrophs

Organisms that consume inorganic compounds for energy
Ex) Bacteria that consumes heat for energy

Passive Transport

Doesn’t require energy, and things move with the grain via diffusion and concentration. They try to balance the two sides of the membrane

Active Transport

Does require energy and proteins to move things against the grain
Ex)

Concentration

How many things is in the cell

Tonicity

The solute concentrations in comparison to something else

Hypertonic Solution

The solution is more concentrated than the cell

Isotonic

The solution is as concentrated as the cell

Hypotonic

The solution is less concentrated as the cell

Facilitated Diffusion

Things are aided to move with the help of proteins but still moves with the gradient
Ex) Carrier proteins or Channel proteins

Channel Proteins

They make a channel/tunnel so the substance can flow right through

Carrier Proteins

They capture the substance within their sites and move them into the cell

Active Transport

Carrier proteins pump the substances in and out of the protein

Primary Active Transport

Moves solutes against the gradient using ATP energy and protein transporters

Secondary Active Transport/Co-transport

Moves things using the changes in ions (electrochemical gradient) with protein transporters, not creating energy to do it but uses energy thats already there

Osmosis

Water moves from low concentration to high concentration

Membrane Components

Lipids, Proteins, and Carbohydrates

What moves across the membrane easily?

Substances that are nonpolar, hydrophobic (lipid-soluble), and have a low molecular weight

What do not move across the membrane easily?

Substances that are polar, hydrophilic (not lipid-soluble), have charged ions, and have a high molecular weight

Diffusion

Does not require energy and works off using concentrations, moves from high concentration to low to make both sides equal

Electrochemical Gradient

Charge differences in the ions

Genome

A double strand DNA molecule

What are the properties inside the membrane

It’s made of fatty acids and is hydrophobic

What membrane component can be found on its surface

Proteins

How does water move in osmosis

From high concentration to low concentration

Does water move in an isotonic solution

Yes

Aquaporins

Proteins that create specific channels for water to easily move in and out of the cell

Crenated

Has a higher solute concentration outside of the cell compared to in the inside and this causes water to get drawn from out the cell, making the cell shrink in size

Lysed

Has a lower solute concentration outside the cell compared to the inside and this causes the cell to expand, making it bigger in size

Plasmolysed

In plant cells when there is a higher concentration outside than inside the cell, this causes water to move out, causing the cell to shrink.

Turgid

When a plant cell swells and expands because there is a lower concentration outside