BISC300 Lecture Notes - Lecture 6: Facilitated Diffusion, Glycerol, Active Transport

• School: University of Delaware
• Department: Biological Sciences
• Course: BISC300
• Professor: Cooper Carlton

Document Summary

Uptake of nutrients-getting through the barrier: growth factors. Esse(cid:374)tial (cid:272)ell (cid:272)o(cid:373)po(cid:374)e(cid:374)ts (cid:894)or their pre(cid:272)ursors(cid:895) that the (cid:272)ell (cid:272)a(cid:374)"t synthesize. Must be supplied by environment if cell is to survive and reproduce. Uptake of nutrients: microbes can only take in dissolved particles across a selectively permeable membrane, some nutrients enter by passive diffusion, microorganisms use transport mechanisms. Passive diffusion: molecules move from regions of higher concentration to one of lower (cid:272)o(cid:374)(cid:272)e(cid:374)tratio(cid:374) (cid:271)et(cid:449)ee(cid:374) the (cid:272)ell"s i(cid:374)terior a(cid:374)d the e(cid:454)terior, water, oxygen, and carbon dioxide often move across membranes this way. Facilitated diffusion: similar to passive diffusion. Direction of movement is from high concentration to low concentration. Size of concentration gradient impacts rate of uptake: differs from passive diffusion. Smaller concentration gradient is required for significant uptake of molecules. Effectively transports glycerol, sugars, and amino acids: more prominent in eukaryotic cells than in bacteria or archaea fa(cid:272)ilitated tra(cid:374)sport i(cid:374)(cid:272)reases tra(cid:374)sport rate (cid:271)e(cid:272)ause it"s (cid:373)ore specific.