Lecture 4 Flashcards
What are the different groups of lipids?
Fats, phospholipids, carotenoids, steroids and waxes
What is the purpose of lipids?
Used for longterm energy storage, structural components of eukaryotic cell membranes and in key hormones
What are eukaryotic cells?
Cells that have a nucleus, organelles and are inclosed by a plasma membrane
Where are waxes found and what is their purpose?
They’re found in plant cells and give leaves their waxy coating to prevent transpiration of water
What is the structure of a fat?
Glycerol and 3 fatty acids
What is another name for fats?
Triglycerides
What is the purpose of triglycerides?
- Form of long-term fuel storage
- The glycogen that our body doesn’t use right away gets stored as fat
Saturated fatty acids?
- Only single bonds
- Solid at room temperature
Unsaturated fatty acids?
- Double bonds
- Liquid at room temperature
What are the two types of unsaturated fatty acids?
- Monounsaturated (one double bond)
- Polyunsaturated (more than one double bond)
What is the structure of a phospholipid?
They’re composed of 2 fatty acid chains, a glycerol, a phosphate, and a polar group
Amphipathic?
When a compound has both a polar end and a non-polar end
Describe the two ends of a phospholipid.
They differ physically and chemically; one end is hydrophilic and the other end is hydrophobic
What are carotenoids role in plants?
- Give plants their orange/yellow colour
- Have a role in photosynthesis
What do animals convert carotenoids to when digested and how?
This molecule is made up of isoprene. It gets cleaved between these different isoprene units, which produces vitamin A and retinal
What is the structure of a steroid?
- Made up of a lot of isoprene units
- Formed into ring structures
What is the function of a steroid, and an example of one?
Involved in regulating metabolism (cholesterol)
What is the function of nucleic acids?
To transmit hereditary information and determine what proteins a cell makes
What are the two classes of nucleic acids found in cells?
DNA and RNA
How are DNA and RNA formed?
Formed from a series of nucleotides joining together by phosphodiester linkage
What are the different nitrogenous bases in DNA?
Thymine & Adenine
Cytosine & Guanine
What are the different nitrogenous bases in RNA?
Uracil & Adenine
Cytosine & Guanine
Phosphodiester linkage?
A phosphate of one nucleotide attaches itself to a carbon atom on the ribose sugar
DNA?
- Double stranded helix
- Carries genetic instructions
RNA?
- Single stranded
- Roles include coding, decoding, regulation and expression of genes
What is the structure of a nucleotide?
A 5 carbon sugar (DNA/RNA), one or more phosphate groups, and a nitrogenous base
Purine?
A double ringed nitrogenous base
Pyrimidine?
A single ringed nitrogenous base
What are two other types of nucleotides and their functions?
ATP - High energy currency of the cell
Cyclic AMP - Cell signaling
What is the general structure of a lipid?
- Soluble in nonpolar solvents and relatively insoluble in water
- Consists mainly of carbon and hydrogen, with a few functional groups that contain oxygen
What is the structure of glycerol?
A 3 carbon alcohol with 3 hydroxyl (OH) groups
What is the structure of fatty acids?
A long unbranched hydrocarbon chain with a carboxyl group (COOH) at one end
What are nucleic acids a polymer of?
Nucleotides
What are nucleotides joined by?
Phosphodiester linkages
