Mononucleotides: Structure Both DNA and RNA are polymers that are made up of many repeating units called nucleotides Each nucleotide is formed from: A pentose sugar (a sugar with 5 carbon atoms) A ...
社会捐赠作为美国大学重要的资金来源之一，是学校提供高质量教学、研究和服务的基本保证！ 近日，UIUC官宣他们已提前达成了“计划在5年时间内实现22.5亿美元慈善筹款”计划，仅仅用了四年，伊大就累计筹得款项27亿...
Osmosis All cells are surrounded by a cell surface membrane which is partially permeable Water can move in and out of cells across the cell surface membrane by a process called osmosis Osmosis is t...
Active Transport Active transport is the movement of molecules and ions through a cell membrane from a region of lower concentration to a region of higher concentration Active transport requires en...
Diffusion & Facilitated Diffusion Diffusion is a type of transport that can occur across a cell membrane Note that diffusion can also happen within a cellular compartment; the presence of a mem...
Practical: Investigating Membrane Structure & Permeability The permeability of cell membranes is affected by several factors such as Temperature pH The effect of such factors on membrane struct...
Cell Membranes Membranes are vital structures found in all cells The cell surface membrane creates an enclosed space separating the internal cell environment from the external environment, and intr...
The Mammalian Lung: Structure & Function The lungs of air-breathing animals provide an ideal exchange surface for the diffusion of gases The lungs are located in the thorax, or chest cavity Som...
Fick's Law of Diffusion Fick's Law relates the rate of diffusion to the concentration gradient, the diffusion distance and the surface area This relationship can be represented by the following equ...
