But yeah, anywhere in your 20s is still young. Early 30s is where that ends. kingkong113 said: â. I ask this because this girl in my Precal class has been all on my dick and is clearly looking to hook up but she is like 28. but she did say and I quote My Pussy is tight though lol who says that to someone.
Active transport. Active transport is the movement of molecules across a cell membrane from a region of their lower concentration to a region of their higher concentrationâin the direction against some gradient or other obstructing factor (often a concentration gradient).
Sometimes diffusion is too slow or cell need to take or get rid of substances against a concentration gradient. Cells achieve this task by a special process called active transport. Active transport is the movement of substance across the cell membrane against a concentration gradient. Unlike the osmosis, active transport needs a great deal of energy, which has to be obtained from ATP. Active transport is achieved with the help of carrier protein in the plasma membrane. Usually the ions like Na+, Cl- and K+, and the molecules like glucose, amino acids, and vitamins are transported by active transport. For example, plants absorb mineral ions by using active transport.