Essays Tagged: "plasma membrane"

Cystic Fibrosis

flow of chloride ions into and out of certain cells. In healthy people, CFTR forms a channel in the plasma membrane so chloride ions can enter and leave the cells lining the lungs, pancreas, sweat gla ...

(4 pages) 141 1 4.2 May/2002

Subjects: Science Essays

Steroid and non-steroid hormones differ in how they affect target cells. Describe the mechanisms involved using specific examples of each. How is it that hormones affect some cells and not others?

on in their target cells. These hormones are lipid soluble and can diffuse directly through the the plasma membrane of a cell to bind with special receptors in the nucleus. Once the steroid hormones a ... varies are stimulated to produce eggs.Non-steroid hormones, such as insulin, cannot diffuse through plasma membrane. These hormones influence cytoplasmic activities through a second messenger, cAMP (c ...

(1 pages) 26000 2 3.8 Jan/2003

Subjects: Science Essays > Biology > Human Biology

Discuss the hormones in plants and their actions. (auxin, gibberellin, cytokinin, abscisic acid, ethylene)

plants towards light and water. It also makes trees produce more xylem for thickness. Auxin causes plasma membrane to transport four ions out o the cell. Synthetic auxins are used to kill weeds. Agen ...

(2 pages) 84 2 4.6 Mar/2003

Subjects: Science Essays > Biology > Plant Biology

Experiment with Diffusion, Osmosis, and Hypertonic Solution. Discusses what each is, along with how the experiment was done in a lab.

her solution is called a Hypotonic Solution. A cell that has a Selectively Permeable Membrane has a plasma membrane that allows certain substances to pass through more readily than others.From this I ...

(2 pages) 149 2 4.6 Aug/2003

Subjects: Science Essays > Biology

Biology notes on genetics.

m's single DNA molecule is not coiled around proteins to form chromosomes. Instead, its face of the plasma membrane like a rope attached to the inner wall of a tent. First the DNA is copied, and then ... cell has two identical copies of its hereditary information, attached side by side to the interior plasma membrane.Once the DNA has been copied and the cell has grown to an appropriate size, the bact ...

(5 pages) 129 2 2.4 Aug/2003

Subjects: Science Essays > Biology

All about Bacteria.

a spiral cell. A few kinds of bacteria aggregate into stalked structures or filaments.A bacterium's plasma membrane is encased within a cell wall. Members of the kingdom Eubacteria have a cell wall ma ...

(5 pages) 152 1 4.8 Aug/2003

Subjects: Science Essays > Biology

Eukaryotic Cells, all organelles explained with functions.

ll, or develops a second, stronger wall, called the secondary cell wall, which develops between the plasma membrane and the primary cell wall.Cytoskeleton also provides structural support for the cell ...

(4 pages) 106 0 4.0 Nov/2003

Subjects: Science Essays > Biology

Module 1 biology notes

do not have nucleus. Only bacteria have prokaryotic cells. They are surrounded by a cell wall and a plasma membrane. Some are surrounded by a capsule. Ribosomes are the only organelles found in their ... y a nuclear envelope. Organisms other then bacteria have eukaryotic cells. They are surrounded by a plasma membrane. Some are surrounded by a cell wall. Their cytoplasm contains a variety of organelle ...

(4 pages) 46 0 3.7 Feb/2004

Subjects: Science Essays > Biology

Ion channels

of inorganic ion homeostasis within the cell by selectively importing and exporting ions across the plasma membrane. These proteins form a hydrophobic pore across the membrane to connect the extra cel ... as five major domains. These domains include two nucleotide binding sites, two regions the span the plasma membrane as well as a regulatory domain. The two transmemebrane proteins are believed to form ...

(6 pages) 42 0 0.0 Mar/2004

Subjects: Science Essays > Biology

The effect of temperature on the cell membrane of a beetroot.

PlanningAimIn this experiment I will be testing the effect of temperature on the plasma membrane of a beetroot. I will do this by measuring the percentage light transmission using a ... ined are correct, and are a true reflection of the effect of temperature on the permeability of the plasma membrane of a beetroot.In my graph I will be analysing the general trend of the line (or curv ... e is increased, an increasing number of extrinsic, intrinsic and glycoproteins imbedded in the cell plasma membrane of beetroot cells, become denatured.EvaluationThe reasons for anomalous data;In my r ...

(10 pages) 132 0 4.3 Apr/2004

Subjects: Science Essays > Biology


9.1 PLASMA MEMBRANEI. All cells must maintain homeostasis in order to live.- they do this by controlling ... order to live.- they do this by controlling what materials can enter and leaveII. All cells have a plasma membrane that is SELECTIVELY PERMEABLE - this only allows for specific things to enter and le ... fic things to enter and leave the cellA. Selective permeability is achieved by the structure of the plasma membrane (fig.9.3, pg 220)1. The cell membrane is composed of 2 layers of PHOSPHOLIPIDS -"pho ...

(2 pages) 39 0 4.3 May/2004

Subjects: Science Essays > Environmental Science

The Effect Of Temperature On a Cell Membrane's Permeability

This experiment aims to determine what effect an increase in the surrounding temperature has on the plasma membrane of a typical plant cell structure.Hypothesis:An increase in temperature will damage ... f a typical plant cell structure.Hypothesis:An increase in temperature will damage and denature the plasma membrane and cause the cytoplasm and other substances contained within the membrane to leak o ...

(5 pages) 111 0 4.7 Jun/2004

Subjects: Science Essays > Biology

Cellular level organization.

nge in size from a frog's egg (one millimeter) down to one micrometer.2. Cells need surface area of plasma membrane large enough to adequately exchange materials.3. Surface-area-to-volume ratio requir ...

(1 pages) 600 0 4.0 Nov/2005

Subjects: Science Essays > Biology

Cell walls revised.

a cell wall, large central vacuole, and plasmodesmata.Like other eukaryotes, plants have a nucleus, plasma membrane, mitochondria, and other organelles, but plant cells differ from animal, fungal, and ...

(2 pages) 16 0 0.0 Dec/2005

Subjects: Science Essays > Biology

Biology - The Movement of Molecules

Every cell is surrounded by a plasma membrane. The cell membrane is selectively permeable- only certain substances can cross it fr ...

(2 pages) 30 0 5.0 Feb/2006

Subjects: Science Essays > Biology

The Activity of Sodium-Potassium Active Transport with respect to the Concentration of Cytoplasmic Sodium

Due to the nature of amphotericity and the conformation of plasma membrane, large or ionic molecules can not permeate through plasma membrane freely. To help w ...

(3 pages) 19 0 0.0 Mar/2006

Subjects: Science Essays > Chemistry

Tests for various biological molecules and their properties

hydrophobic and not soluble in water.Function:Serves as store for energy, insulation, formation of plasma membrane, buoyancy for animals, form a layer around organs and hence serve as a layer of prot ...

(3 pages) 14 0 0.0 Sep/2006

Subjects: Science Essays > Biology

Comparison of prokaryotic and eukaryotic cells

nucleus is usually not located in the center of the cell; rather, it is usually crowded nearer the plasma membrane. In most animal cells, however, the nucleus is located in the center of the cell, as ... the nucleus from the cytoplasm of the cell. The membrane is a phospholipid bilayer, similar to the plasma membrane that bounds the cell. The phospholipid bilayer is visually represented in figure C. ...

(14 pages) 55 0 0.0 Feb/2008

Subjects: Science Essays > Biology

The Plant And Animal Cells

nding the nucleus and other organelles is cytoplasm. It is a clear liquid, which is enclosed by the plasma membrane, and is where many chemical reactions, such as protein synthesis, take place. Cytopl ... job, which are the cilia and flagella. The cilia are short hair-like projections that come from the plasma membrane (which is the flexible boundary between the cell and its outside environment). They ...

(4 pages) 23 0 0.0 Feb/2008

Subjects: Science Essays > Biology

Testable Question Is it possible to observe diffusion across a

r concentration to a region of lower water concentration. Plant cells have a cell wall as well as a plasma membrane. The cell wall is a rigid structure that is used by the cell to create osmotic press ...

(2 pages) 2474 0 0.0 Feb/2008

Subjects: Science Essays > Chemistry