Cell surface or membrane is made of phospholipid bilayer with embedded proteins and sugars. Cell membrane acts as a barrier between cell and its external environment but it is also responsible for the communication with other cells and transport of molecules inside and outside the cell. It is selectively permeable to ions and molecules (some of them pass through the membrane easily, while others require transport proteins or channels). There are 4 ways of molecule transport:
1. Diffusion – no energy required
2. Facilitated transport – transport proteins included
3. Active and co-transport – energy required
4. Vesicle transport (exocytosis and endocytosis)
Microvilli are extensions of cell membrane that increase its surface for diffusion.
Different types of cell junctions have a different influence on the membrane transport. For example, tight junctions are a barrier and the molecules are unable to pass through.
Increase levels of oxygen in seawater, evolution of eyes, origin of hard parts, and genetic changes
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New discoveries influence contemporary psychological perspectives because they provide new ways to look at things, or give new technology for new ways to diagnose problems and try to solve them.
Answer:
Essay
Explanation:
In this modern world, due to advance information technology various means of communication is used for different purposes. For sending documents from one place to another, people use communication medium such as e-mail. For giving message through their voice, people use communication medium such as voice chat. Video chat is also a communication medium used by the individual to chat with their friends and relatives through live video. These communication mediums make the world into a small village where people interact with each other which are present at a large distances.
Answer:
Starch
Explanation:
I'm assuming that we are talking about plants and plants store extra glucose as starch molecules.
