Exam 1 study guide questions Flashcards
Glucose
a reducing sugar within the cell- burned in glycolysis to create ATP and carbon skeletons for amino acids, fats, and secondary metabolites.
Sucrose
disaccharide, combining 1 glucose with 1 fructose. A non-reducing (less reactive) sugar that is loaded into the phloem for transport throughout the plant.
Starch
a polysaccharide made of glucose monomers. This is made and stored in the plastid. It can also be broken down by amylases into maltose or glucose for later use.
Cellulose
this is part of the cell wall, also made out of glucose, and is a structural component of the cell. However, unlike starch, it cannot be broken down by the plant and thus represents permanent loss of energy.
What are the primary lipids in a plant, where are they located?
Polar glycerolipids: major component of cell membranes
Triglycerols: primary storage lipid in plant cells
Why are different membranes composed of different lipids?
-Lipids are made specifically to be tailored to the needs of the particular organelle
List the key steps in the production of a fatty acid starting with pyruvate and acetyl-CoA.
-fatty acid biosynthesis is in the plastids
-it is facilitated by a fatty acid synthase and the acetyl carrier protein
-elongation relies on the the addition of two acetyl-CoA units at a time
How does animal and plant fat metabolism differ?
Animals
-Store fat in adipose cells
-Release stored energy in times of hardship
Plants
-Store lipids in vacuoles, seeds, oil bodies
-Lipids are reserved for long term energy storage
-Have a wider diversity of lipids for different purposes
Do all plants have the same primary and secondary metabolic pathways?
Not all plants share the same enzyme composition genes, so while metabolic pathways may be similar, they can’t all be identical. Plants may evolve secondary pathways that involve more reactions to compensate for the lack of that particular gene needed to make the enzyme they need.
What are some of the functions of secondary metabolites?
-Phenolics: can be used for a wide variety of purposes (ie. lignin)
-Terpenes: largest group, growth and development (ie. gibberellins)
-Alkaloids: pharmacological effects (ie. morphine)
Are primary metabolic pathways different to secondary ones? How do we define these pathways?
Primary metabolic pathways tend to be essential for life and conserved across most plants. (ie. photosynthesis) Secondary metabolic pathways tend to be more species specific and diverse. (ie. UV protection, pest defense)
Describe the different kinds of online databases that are available for examination of metabolic pathways, genes and genomes.
-Genome Databases: genes, function, chromosomal DNA, proteins
-Organism Databases: research, tools, stock center
-Metabolic Pathway Databases: links enzymes to metabolites, describe enzyme function
How would you use KEGG to find which metabolites are in a pathway, or which pathways use a particular metabolite?
Search the pathway you want to research. There should be several circles linking the reaction arrows. These represent the metabolites in the pathways. Click on the circles to see more information regarding that particular metabolite. It will show you all the known information about the metabolite, including other known pathways it is a part of.
