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Secondary Active Transport

By: HWC, Views: 7196

Energy stored (in a hydrogen or sodium concentration gradient) is used to drive other substances against their own concentration gradients Secondary active transport, is transport of molecules across the cell membrane utilizing energy in other forms than ATP. In many cells, antiporters mov...

What are the Parts of a Plant Cell?

By: HWC, Views: 5709

Every chloroplast in a plant cell is packed with stacks of flattened sacs called thylakoids. The thylakoid membranes contain chlorophyll, as well as most of the other components required for the light reactions of photosynthesis. The chlorophyll-containing structures within the membranes are c...

Regulation of GFR: autoregulation via myogenic mechanism Myogenic mechanism

By: HWC, Views: 8146

• GFR can be regulated by adjusting: • Blood flow in and out of the glomerular capillaries. • Surface area of glomerular capillaries. • There are three main ways to make these adjustments: • Renal autoregulation. • Nervous regulation. • Renal autoregulation occurs when...

Glycolysis - and oxygen

By: HWC, Views: 6895

The first reactions involve a single 6-carbon glucose sugar undergoing phosphorylation using two ATP molecules and resulting in two 3-carbon compounds. • The rest of this pathway involves an oxidation reduction reaction, forming two reduced coenzymes, and generation of four ATP molecules. ...

Regulation of GFR: autoregulation via tubuloglomerular feedback, neural & hormonal regulation

By: HWC, Views: 7826

• When blood pressure is above normal, rapid filtrate flow reduces ion retention so filtrate in tubule has more Na+, C1-, and water. • It is believed that vasoconstricting chemicals from the juxtaglomerular cells are released when the macula densa cells detect higher water and ion levels in ...

Bulk flow - Factors that influence bulk flow

By: HWC, Views: 6906

• Bulk flow helps regulate the relative volumes of blood and interstitial fluid. • Flow from blood to interstitium is called filtration. ■ Flow from interstitium to blood is called reabsorption. ■ Four factors determine the net direction of capillary exchange. ■ These factors in...

Metabolic Rate, Heat and Thermoregulation - response to heat and cold stresses

By: HWC, Views: 6885

• A neuron group in the anterior portion of the hypothalamus controls heat balance. • Neurons in the preoptic region of the hypothalamus integrate signals that come from thermoreceptors. • The temperature control center in the preoptic region propagates control signals to two other part...

Negative Feedback Regulation of Blood Pressure

By: HWC, Views: 6661

stimulus • Blood pressure determines the flow of blood to and from capillaries. • Low blood pressure results in reduced blood flow. • High blood pressure can cause blood vessels to break. Baroreceptors • The aortic arch carries blood to the body. • The common carotids ca...

Pressure Flow Model Animation

By: HWC, Views: 5872

This apparatus of beakers A and funnels simulates the flow of a sucrose solution in the phloem of a plant. The funnels and connecting tube represent a sieve tube of the phloem. Differentially permeable membranes cap the funnels at the source and sink ends, allowing water, but not sucrose, to cros...