The cell membrane is selectively permeable, allowing only certain substances to pass through. Passive transport is a way that small molecules or ions move across the cell membrane without input of energy by the cell. The three main kinds of passive transport are diffusion, osmosis, and facilitated diffusion.
Answer:
that's not a good idea, most teachers search the web to check for plagiarism, and if they did they would see this question. but I'd say to go over the main facts, such as their diet, their ecosystem, and animals that prey on them. then add a few facts as space fillers if you need to.
When a signaling molecule binds to the GPCR, the G protein alpha subunit exchanges GDP for GTP. The alpha subunit dissociates from the beta and gamma subunits and interacts with other molecules, ultimately triggering a cellular response. ... GTP is hydrolyzed to GDP, and the signaling molecule comes off of the receptor.