motion. Kinetic energy causes molecules to bump into each other and move into different places. Diffusion is the random movement of molecules from an area of higher concentration to an area of lower concentration. Cells have selectively permeable membranes that only allow the movement of certain solutes. Diffusion is vital for many of life’s functions in a cell. It allows oxygen and carbon dioxide exchange in the lungs and between the bodies of intracellular fluid and cells. An example of this…
Each lectin molecule usually comprises of two or more carbohydrate-combining sites, i.e., they are di- or polyvalent. Concanavalin A (a tetramer protein originally extracted from the jack-bean, Canavalia ensiformis) is a member of the legume lectin family and is a particular lectin that has been observed to be able to agglutinate a multitude of cell types, including myocytes, B-lymphocytes and fibroblasts, but for it to perform this action, it needs the presences of sugars which include mannose…
be skipped in a tissue-specific manner forming the IR isoform A. This contributes to the major functional difference between the two isoforms, such that isoform A has more affinity for IGF-2. (1) Occurrence Insulin receptor occurs in the plasma membrane of a variety of cells in brain (olfactory bulb, hypothalamus, cerebral cortex, cerebellum, hippocampus, neurons, and pituitary lobe), kidney, liver (heapatocytes), heart, lungs (pulmonary alveoli),…
fold. This fold contains helices encasing a small water-conducting channel where water is able to arrange in a singular line. There are cytoplasmic and extracellular loops immersing into the membrane through opposing sides, and form two smaller helices creating a psedo transmembrane segment. Within the membrane, there are four aquaporin molecules forming a homo-tetramer, creating a fifth channel; the channel is mainly hydrophobic. However, they are some structural differences, as well as…
Membrane Self-Assembly Processes: Steps Toward the First Cellular Life by Pierre-Alain Monnard & David W. Deamer Summary: To summarize, early cells must have had a membrane to encapsulate its components and keep them within the cell. This membrane was made up of amphiphiles. This membrane was very permeable and as a result, passive diffusion occurred. Later on this membrane evolved to be a little impermeable as to keep the metabolic reactions and catalysts that drive these reactions within…
Diffusion Across a Plasma Membrane Lab The purpose of this lab was to learn about the permeability of plasma membranes. In this experiment, dialysis tubing was used to simulate the semipermeable plasma membrane of a caterpillar’s intestine. Cooked starch was prepared and mixed with the enzyme amylase to simulate the mixing of the caterpillar’s saliva with a starch/leaf and then placed in the dialysis tubing to simulate the beginning of the digestive process. The enzyme amylase breaks down…
science, it’s said that cell tissue can be permeable, this means that the cell tissue can regulate what fluids or airs travel through the membrane. For a cell to be able to have that kind of attribute, it permits us to conclude that cell tissues contribute significantly in passive transport. Passive transport is the measure of constituents through the cell membrane minus any involvement of energy by the cell. This experiment was done in order to govern how osmosis occurs in two different…
The Effects of Temperature on Cellular Membranes Kean University: Biology 1300 Section 3 Liyet Iran Partners: Paoline Medina, Jennifer Yuen, Christian Gonzalez, D’wan McCrary, Nicole Piscatelli November 12, 2015 Abstract The cell membrane is an essential structure of any cell. It’s the structure that protects and support the cell. To determine whether this structure can withstand hot or cold environment, a beet specimen is put to test. Six consistent cylindrical beet will…
Resting membrane potential is the difference in voltage of the fluids inside a cell and outside a cell and the membrane is said to be polarized. According to the book the value of the resting membrane potential varies from -40 mv to -90 mv in different types of neurons. There are two essential factors that build and generate the resting membrane potential: the differences in the ionic composition of the intracellular and extracellular fluids, and the differential permeability of the plasma…
by their structure they both have a number of features in common but all so lots of differences. The eukaryotic cell has a membrane enclosed organelle called the nucleus. This is where the DNA in the cell can be found. However the prokaryotic cell does not have a nucleus. The DNA in a prokaryotic cell is found in an area of the cell call the nucleoid this has no membrane separating it from the rest of the…