chapter 1 - intro Flashcards
Arabidopsis thaliana
- first flowering plant genetically sequenced
- weedy plant
What is the difference, ecologically, between producers and consumers?
- producers: make their own food, like photosynthesis
- consumers: cannot make their own food, eat producers
Could life on earth exist without plants?
No, plants emit oxygen that we need & they are the primary producers.
What percentage of the biomass is made up by plants?
85-90%
What gives rise to the 3 domains of life?
Differences in DNA sequence or genome
What are the 3 domains of life?
bacteria, archaea, eukarya
What are some examples of genes shared between plants and animals?
- regulator genes
- Rep, transcription, translation enzyme genes
- ribosomal genes
Characteristics of Fungi
- eukaryotes
- cell walls with chitin
- heterotrophic / consumers
- storage carb= glycogen (like animals)
- more characteristics similar to animals than plants
Algae
- Non-specific grouping of aquatic photosynthetic life
- “green stuff in water”
Characteristics of plants
- eukaryotes
- mostly autotrophic / producers
- some (few) are heterotrophic
Land plants
- mosses and liverworts (bryophytes)
- ferns, fern allies (seedless vascular plants)
- gymnosperms
- angiosperms (monocots or dicots)
What plants were dominant in Mesozoic time?
gymnosperms
Angiosperms came from gymnosperms due to what?
- diversification of flowering plants
- diversification of insect pollinators
- BOTH of these were needed and enhanced each other
What plants are dominant today or in Cenozoic time?
- angiosperms dominate plant biomass
- except on placed w higher altitudes like canada
What is mycology?
The study of fungi
How did cockleburs lead to Velcro?
cockleburs stick to clothes, they have hooks that allow them to stick to clothes via loops
- Velcro mimic the hook and loop structure
How did hedge apples lead to barbed-wire fence?
- the stem of hedge apples has thorns
- barbed wire fencing mimics the stem with thorns
- they attract plants to disperse their seeds
- keeps spiders and insects away?
What are the characteristics of life?
- made of organic molecules
- made of cells
- respond to the environment
- evolution
Made of organic molecules explanation
- organic molecules are needed for metabolism and energy
- all living things need them to metabolize and create energy
Made of cells explanation
- every living things is made up of cells
- cells divide to make new cells
- cell division eventually leads to reproduction
Respond to the environment explanation
- all living things respond to stimuli in the environment
- response occurs via different mechanisms depending on the organism
Evolution explanation
- everything comes from pre-existing life that has evolved
What are the four molecules of life?
- carbs
- lipids
- proteins
- nucleic acids
Plant carb main transport form
sucrose, transported to other parts of the plant
Plant carb main storage form
starch, needed for sprouting because it is broken down for energy before a plant can photosynthesize
Plant carb main structural form
cellulose, makes up plant physical structure
Amylose vs Cellulose
Amylose
- alpha-glucose linkages
- humans have enzyme to break down
Cellulose
- beta-glucose linkages
- humans do NOT have enzymes to break down (will not give us energy)
- plants, bacteria, and archaea do have the enzymes to break it down
Proteins
- made of amino acid
- organized in polypeptide chains
Functions of proteins
ribosomes, membranes, transport, cell structure, ENZYMES, cell regulation, energy storage…
Lipids
- non-polar hydrocarbons
- stored as triglycerides in plants
- can be saturated or unsaturated
Which part of the pant contains the most lipid?
the seed
- has evolved to have oil, where oil comes from
- have higher energy output per gram of material that is needed for germination
Do plants have more saturated or unsaturated fats?
- unsaturated fats
- because at room temp they are liquid
- liquid form is oil
- unsaturated fats don’t pack as tightly and are more fluid - allows better function in cooler plant temps
Other functions of lipids?
- energy storage
- membranes
- waxes, cutin on the outside of plants
Nucleic acids
- made of nucleotides
- function as genetic information
- needed for rep, transcription, and translation
How much genetic information do you share with a plant?
40%
- cell resp genes
- metabolism genes
- rep. transcription, translation genes
- cell cycle and mitosis genes
- signaling molecules
- eukaryotic organelle genes
Plant secondary products
organic compounds produced by the plant but not absolutely required for growth and development
What are the four plant secondary products
- terpenes
- phenolics
- glycosides
- alkaloids
Terpenes
- a plant secondary product
- polymers of 5-carbon isoprene units
Examples of terpenes
- menthol
- camphor: medicines
- rubber: plant defense
- taxol: anti-cancer drug
- beta-carotene: photosynthetic pigment
structure of menthol
- 2 isoprene units together
Phenolics
- a plant secondary product
- compounds with unsaturated carbon ring structures (double bond rings)
Examples of phenolics
- lignin: strengthen cell walls in secondary growth, used in 2nd cell walls of woody plants & creates rigid cell wall
- flavonoids: tannins for flavoring & anthocyanins for coloration of fruits/veggies
- urushiol: dermatitis forming compound in poison ivy
- THC: active ingredient in cannabis
Urushiol structure
- phenols with long carbon hydrocarbons
- hydrocarbons are hydrophobic
- washing off with water will not make effect of poison ivy go away
THC structure
- mimic of a normal NT in the brain called anandamide
Glycosides
- a secondary plant product
- sugar bonded to other molecules
- typically bonded to terpenes, phenolics, or steroids
Examples of glycosides
- saponins: from yams and used in production of human sex hormones (similar to female progesterone); a plant-based estrogen that can be chemically converted into progesterone
- digitoxin: used for congestive heart failure; eliminates excess fluid around the heart
Alkaloids
- a plant secondary product
- contain nitrogen in a carbon ring structure
- many affect neurological systems of animals
Examples of alkaloids
- morphine
- cocaine
- strychnine
- nicotine
- caffeine
Why do plants make alkaloids
to deter herbivorous animals
- elicit a bitter taste and potential poisoning
Conium maculatum
- poison hemlock
- an example of an alkaloid
- contains coniine
- deadly
What pathway is associated with the production of plant secondary products?
shikimate pathway
Significance of shikimate pathway
- ONLY in plants
- not in humans (why we need to eat certain aa)
- targeting this pathway could develop effective herbicides that kill plants but limit harm to humans
- eliminating shikimate pathway from plants will lead to their death
- this is what the herbicide round up does
