Medbio Quiz Revision

The chemistry of life is...

1) Overwhelmingly based on carbon compounds, the study of which is organic chemistry.

2) Depends almost exclusively on chemical reactions that take place in aqueous solutions within a specific temperature threshold.

3) Enormously complex.

4) Coordinated by polymeric molecules that allow a cell to carry out its various functions, like growing and reproducing.

5) Tightly regulated; several mechanisms ensure that chemical reactions occur at the right time and place.

An element is...

The simplest form of matter. It cannot be decomposed into simpler substances via normal chemical reactions.

How many naturally occurring elements are there?

90

What are examples of the most common elements found in organisms?

Carbon (C), Hydrogen (H), Oxygen (O), and Nitrogen (N), with other elements like P, K, Ca, Mg, Cl, S, and Na being found less often.

Biomolecules composition:

Primarily of the elements carbon, nitrogen, hydrogen, oxygen, sulfur, and phosphorus.

Postulates of the modern cell theory:

1) All living organisms are made up of cells.

2) The cell is the structural and functional unit of life.

3) All cells come from pre-existing cells via cellular division (mitosis).

4) Cells contain hereditary information (DNA) that is stored in the nucleus and is passed on to other cells via division.

5) All cells have a similar basic chemistry.

6) All energy flow of life happens in cells.

Bond Length is...

The distance between the centers of two covalently bonded atoms. As bond strength increases with bond order (single, double, triple), bond length decreases.

What type of covalent bond binds monosaccharides to one another?

Glycosidic bond/linkage

Define isomers

Molecules (especially carbohydrates) that share the same chemical formula but have different spatial arrangements, like glucose, mannose, and galactose.

Functions of sugars:

1) Energy production: Carbohydrates are the first macromolecules to be broken down and metabolized for energy by the body.

2) Energy storage: They can be incorporated into polysaccharides for energy storage (such as glycogen).

3) Building macromolecules: They are found in a variety of macromolecules, like nucleic acids (DNA and RNA) and ATP.

4) Protein sparing: In the case of low carbohydrate content, the body may choose to break down and destroy proteins to release energy, often weakening muscle tissue.

5) Lipid sparing: When carbohydrate content is high, lipid metabolism for energy is inhibited, thereby "sparing" it from being broken down.

The 3 main types of lipids are

1) Tryglycerides

2) Phospholipids

3) Sterols

Difference between aldehydes and ketones:

Ketones have the carbonyl group positioned inside the carbon chain, while Aldehydes have the carbonyl group on the terminal carbon.

Main functions of lipids:

1) Energy storage: If little to no carbohydrates are present, the body turns to metabolizing lipids to release energy.

2) Structural function: Form the lipid bilayer, which separate the chemical contents of the cell from the outside.

3) Play a role in cell signaling (glycolipids and the glycocalyx).