Introductory Biology

2.3 Chemistry of Cells

Today was the first class I  participated in and I was very surprised how quickly the information was presented. We talked about the chemistry of cells.Everything living is made up of simpler things, called cells. Organisms –> organs à Tissues à Cells à Organelles à Macromolecules assembilies à Macromolecules. Cells are made up simpler things called atoms. Atoms are joined in covalent bonds to stay long lasting. Organic compounds contain 4 types of molecules; carbon, hydrogen, oxygen, and nitrogen. We can split all life into  four types of macromolecules: carbohydrates, lipids, proteins, and nucleic acids.

The complexity of carbon containing molecules comes from the properties of carbon. Since carbon only has 4 valence electrons, they like to make four bonds and have lots of partners ,which creates complexity.

You make all sorts of molecules through condensation. Hydrolysis break all sorts of molecules down. Whenever you make something in your body, you also make water. In your stomach, there has to be water present to break things down. When you consume food, it is mostly broken down and it releases energy. So overall, water is removed in condensation synthesis and is added in hydrolysis.

Carbohydrate contain carbon, hydrogen, and oxygen as a 1:2:1 ratio. They are used to store energy or for structural purposes by organisms. Glucose is a component of many carbohydrates. When two glucoses are linked together, is known as maltose, forming water is through condensation synthesis. When one glucose is linked with fructose it produces table sugar/fructose. Monosaccharide like glucose, ribose, and fructose are usually made of a ring structure. Disaccharides(sucrose and lactose) composed of two monosaccharides joined together. Polysaccharides like cellulose and glycogen, are produced when many monosaccharides are joined together. Humans store glucose in the liver as glycogen.

Monomers = little things

Polymers = big things

Lipids, non-polar molecules, do not dissolve in water  and are fats. They are used to store energy, make membranes. steroid hormones, and other uses by the organisms. They are formed by three fatty acid molecules bonded to one glycerol molecule. Saturated fat are found in animal cells and unsaturated fats are found in plant cells. You can end up with cancer if you consume too much saturated fat, since they have a lot of energy. Every cell has boundaries made from lipids and are built from small pieces of amino acids.

Proteins make the muscles, bones, hormones, enzymes, hemoglobin, and etc. and are produced by many amino acid molecules joined together. Amino acides join together to make polypeptides.  They are the complex molecules that produces the bulk of the dry weight of organisms. They do everything, like make up your structure, regulate contract, immunological. Every protein is a long chain of amino acids. Collagen is a type of protein that makes your skin and hemoglobin carries all the blood cells in the body.

Nucleic acids contain information to build proteins and are made up of nucleotides. Nucleotides are linked together by condensation. DNA is the nucleic acid that contains the genetic information that can be passed on through generations. They have 4 letters: T, A, C, G and they always will match up together in only one way. RNA is another type of nucleic acid  that makes proteins from the information copied from the DNA. ATP is a nucleic acid that supplies energy to run chemical reactions in cells.

After I re-read my notes, I realized that the first few things on my paper caught my attention. “Complex things (like yourself, or a tiger) can only exist because of the complexity it emerges from the simpler parts. Every living thing (complex things) is made up of simpler things, called cells. ” I realized that this statement is connected with the essential unit question: how does complexity emerge from simplicity?


One thought on “2.3 Chemistry of Cells

  1. Yurika,

    Good job with your post. Sorry if the speed of the lesson is too fast!!

    Your blog shows that you’re processing the information well, and also contextualizing the details within the larger context of the essay question.

    Mr. F.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s