Unit 4 Flashcards
Why is carbon important in biological molecules?
Carbon is an element present in all biological molecules.
Why can biological molecules be very large?
Because carbon atoms can form chains or ring structures, biological molecules can be very large.
What are large biological molecules called?
Macromolecules.
What elements are always present in a biological molecule?
Carbon, oxygen and hydrogen are always present in a biological molecule.
What are macromolecules also called?
Polymers.
What is a compound containing carbon called?
An organic molecule.
What are polymers made up of?
Smaller repeating units, these are called Monomers.
What do carbohydrates ONLY contain?
Carbon, oxygen and hydrogen.
What are monosaccharides?
Monosaccharides are the simplest unit of carbohydrates and cannot be broken down any further.
What are disaccharides?
Disaccharides are sugars which have two carbon rings.
What are polysaccharides?
Polysaccharides are carbohydrates made up of many monosaccharides.
What are plastids?
Organelles in plant cells which are sites where molecules are stored and produced.
Are polysaccharides soluble in water?
No.
What are three examples of polysaccharides?
- Starch
- Glycogen
- Cellulose
What elements are lipids made of ONLY?
Lipids ONLY consist of carbon, oxygen and hydrogen.
What is a molecule of fat made of?
Three molecules of an organic acid, called a fatty acid, combined with one molecule of glycerol.
Where are lipids usually found?
Lipids usually form part of the cell membrane and internal membranes of a cell. Eg. The nuclear membrane.
Out of carbohydrates, lipids and proteins, which stores the most energy?
Lipids.
What are lipids soluble in?
Hydrophobic solvents. Lipids ARE NOT soluble in water.
What are the main functions of lipids?
- Long term energy storage.
- Protection against heat loss (they insulate).
- Protection against physical shock.
- Protection against water loss.
- Chemical messengers (hormones)
- Major component of cell membranes (this type of lipid is called phosphilipids).
What are the two types of proteins?
Structural proteins and enzymes.