date martes, 6 de abril de 2010

Class: 7

Date: march 5 / 10

Item: osmosis

TRANSPO.GIF (514×298)


Is when nutrients or ions enter and leave; but the cell don’t spend energy.

The osmosis occurs for the concentration has been equals inside and outside of the cell.

The osmosis occurs in presence to a cell membrane.

Class: 8

Date: 09/03/10

Item: diffusion process and active transport


Is the spontaneous movement of particles from an area of high concentration to and are of low concentration.

Active transport:

Is when the cell spends energy, to transport molecules across the membrane, there are two types of passive transport endocytosis and exocytosis. Is when the cell enters as water and nutrient substances.

Endo= adentro

There are two types of endocytosis

1. Phagocytosis 2. Pinocytosis}

Phagocytosis: is the entry of nutrients through the membrane with energy spent.

Pinocytosis: the entry water into the cell, the membrane invaginates and forms a vacuole that waters enter in to the cell.

Exocytosis: the output of waste outside the cell in this process the cell spends energy.

date sábado, 13 de marzo de 2010

Class: 6

Date: march: Tuesday 02/10

Item: membrane transport

Membrane transport: it is entry and exit of nutrients thought of the membrane by pores or proteins.

Passive transport: The substances entry and exit without energy spend

Active transport: Entry and exit of nutrients and waste with energy Spend.

Passive transport:

the cell you want to find a balance between the concentration of salts internally and externally, to make this happen equilibrium enters the cell and removes ions.

Concentration gradient: the movement of ions according to the concentration of salts internally and externally.

By extreme conditions when concentrations as the cell must make an effort to enter on or remove ions. there are two states called plasmolysis and turgor.

Plasmolysis: when there is a greater concentration of salts or ions inside the cell and must work to remove them to the point that it loses all its water and plasmolisa and still not finish to balance out the salts.

Turgor: when there are many salts or ions and the cell has to enter them and not stand up and explodes.

date sábado, 6 de marzo de 2010


What is active transport?
Answer:Active transport is the mediated process of moving molecules and other substances across membranes.
what is passive transport?
Passive transport or diffusion. Passive transport is the simple exchange of molecules of a substance across the plasma membrane, during which no expenditure of energy that provides the cell.
What is concentration gradient?
Concentration gradient is the difference in solute concentration between two solutions or media.An example: you have water in a container to which you add salt, but do not shake, by the time you add the salt, the highest concentration of salt will be at the bottom of the container, while the higher the concentration is minimal. This difference is the gradient.
what is osmosis?
Osmosis is a physical-chemical phenomena related to the behavior of water as a solvent for a solution to a semipermeable membrane for the solvent (water) but not solutes. Such behavior involves a simple diffusion through the membrane, without "spending power". Osmosis is an important biological phenomenon for cellular physiology of living beings.
What is broadcast?

Diffusion is a physical process irreversible, in which material particles are introduced into an environment that was initially absent, increasing the entropy of the joint formed by the scattered particles or solute and the environment in which diffuse or solvent.
Usually diffusion processes are subject to the Fick's law. The permeable membrane may allow passage of particles and solvent always in favor of concentration gradient. The release process requires no energy input, often as a form of cellular exchange.

date lunes, 1 de marzo de 2010

Homework :

1)How is formed the cell membrane?

Plasma membrane prokaryotes, eukaryotic cell membrane, phospholipid membrane, selectively permeable cell membrane,
cell wall membrane, plasma membrane cytoplasm cell membrane pores, membrane substances.

2) As it is called the model explains the structure of the cell membrane?

The fluid mosaic model is, in biology, a model of plasma membrane structure proposed in 1972 by S. J. Singer and Garth Nicolson thanks to advances in electron microscopy.

3) Who discovered the cell membrane model?

In 1972, Singer and Nicholson proposed the fluid mosaic model. This was possible thanks to advances in electron microscopy, the hydrophilic interaction study, the study of noncovalent bonds such as hydrogen bonding and the development of techniques such as contrast criofractura and negativo.

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S. Jonathan Singer

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Garth Nicolson

date lunes, 22 de febrero de 2010

Membrane Transport: The cell biology of membrane transport is called the set of mechanisms that regulate the passage of solutes, such as ions and small molecules across cell membranes, ie lipid bilayers that have proteins embedded in them.

Mind is a selective permeable barrier, since it prevents the free exchange of materials from one place to another, but at the same time provide a means for communicating a space with another;

Allows the passage or transport of solutes from one side to another cell, it regulates the exchange of substances between the interior and exterior of the cell down a concentration gradient;

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date sábado, 20 de febrero de 2010

Class: 3

Date: February. Tuesday 16/10
Item: Review the cell

Robert Hooke:

Jean baptiste von helmont: created the first microscope; and saw a drop of water and discover the protist.

Matias Schleiden
= developed the cell theory.
Theodor Schwann

Cell Theory

Its has three postulates.
1. The cell is unity of structure.
2. The cell is unity of function.
3. All the living things are formed by cells.

The Cell


Nucleus: Is a structure inside
The cell: its function is the control and direction of the cell. The nucleus is formed By:
nucleolus: Its function is to do ribosomes.

Nuclear Membrane: Its formed by phospholipids and proteins.
Its function is give shape to nucleus.
inside of the nuclear membran we can find NUCLEAR JUICE.

The nuclear juice: Its a liquid made by DNA and RNA
Ribosomes: They are in all places of the cell; they was created in the nucleus. The ribosomes produce proteins that are used in the construction of the membranes.
Chromosomes: They are responsible by the genetic information.

Celular Membrane

Is a structure most important; their functions are:
- Protect the nucleus and cytoplasm
- Give form to the cell
-To allow change of nutrients

date martes, 16 de febrero de 2010