Macaelaa Rangel

What is a cell?

A cell is the smallest structural and functional unit of an organism, typically microscopic and consisting of cytoplasm and a nucleus enclosed in a membrane. Microscopic organisms typically consist of a single cell, which is either eukaryotic or prokaryotic.

Why do we learn about cells?

When you think about the fact that you started out as a single cell, why wouldn't you want to learn about how cells divide, let you do your favorite things, contribute to disease and aid the development of treatments or cures that you one day may need! By understanding how cells work, we can better understand what happens when things go wrong.

What do all cells have in common?

  • Cell membrane
  • Contain DNA
  • Ribosomes
  • Cytoplasm

"Your body has something in the neighborhood of 40 trillion cells - quite a consulting committee. Call on it when you're confused or undecided. Relax quietly and ask your body what it has to say."

How do eukaryotes and prokaryotes reproduce?

  • The life of eukaryotic cells is characterized by a cell cycle with two major phases: the interphase and cell division. During the interphase, the cell takes in nutrients, grows, and duplicates its chromosomes.
  • Prokaryotic cells reproduce by a process that is called binary fission. The DNA in such cells is contained in a single circular chromosome called a plasmid within the cytoplasm. The reproductive process starts with the replication of the chromosome.

If cells make up us, what makes up cells?

Cells are made of organic molecules, such as lipids, carbohydrates, nucleotides and amino acids. The cell uses chemical energy to make polymers of these molecules, for example to make DNA and RNA strands from nucleotides and proteins from amino acids. Cells also contain inorganic molecules, such as salt and metals in small amounts, and lots of water, too.

Why is exercise good for your cells?

Exercise is good for your cells and your tissues because it helps to "train" them so they perform better. For example, muscle cells will produce their energy molecules better and lung cells will be able to use oxygen more efficiently. Exercise also is good for your health because it increases the release of molecules that will boost your body's immune system.