Exam 2 Flashcards
Nutrition
The food we eat, air we breathe, water we drink, supplements we ingest, and all that we do that literally feeds or nourishes the body for its own health benefit
Conditionally essential AA
AA that are only required during stressed or diseased conditions
DO we need to know the ones
One vitamin we can synthesize without food
Vitamin D
B/c it is a hormone
Synthesized in skin, melanin will block UV and thus blocks VitD synth
Do we need to know specific vitamins
Vitamin C
Ascorbic acid
Powerful vitamin for immune function and oxidative stress
Minerals
Need trace amounts to survive on top of CHONPS
Digestion
The breakdown of macromolecules & essential nutrients into the smaller bare molecules
Complete digestive system
Food goes in one end and waste out the opposite, some organisms have waste and food in same hole
Digestion flow chart
GO over the flow chart
Where does digestion begin
Mouth (biological answer)
Cooking and chopping makes digestion easier for us
Mouth
Mechanical digestion: teeth and tongue break food down into smaller pieces
Chemical digestion: Salivary glands produce saliva with chemical enzymes to break down food
pH = 6-7
Chewing and metabolic rate
Increases metabolic rate by 10-15%, about a kcal a min
Salivary Amylase (Ptyalin)
Enzyme in saliva that breaks down starch to maltose
pH 6.5-7
Major components of saliva
Mucus, Amylase, lingual lipase, electrolytes, proteins and enzymes
(99%) water
Taste buds
Different for everyone
Mini pores with “hairs” on the tongue
Lingual (mouth) lipase
produced by tongue (activated by taste)
Breaks triglycerides into FA and glycerol
Most active at a pH of 3.5 so travels to stomach to be active
Peristalsis
Involuntary muscle contraction to move food to the stomach
Aided by water, exercise and fiber
Takes ~6 seconds
Stomach
Uses sphincters to churn up food in acid enzyme mix to break it down further
Storage for ~4 hours
Eating too much or things that are hard to break down you can feel it churning.
Stomach acid (hydrochloric acid)
pH around 1.5-2 to break through tough proteins and other essentials
Mucous layer keeps pH in check
Peptic ulcer
Hole in your stomach
can be caused by disease or bad diet
Pepsin
Main enzyme in stomach for protein breakdown
Regulated by pH (active at <3)
low pH releases it zymogen (pepsinogen) allowing pepsin to work
Lipase
Breakdown lipids in stomach
Lipid digestion
Mechanical churning of the stomach also keeps hydrophobic molecules separated from coalescing. Smaller droplets are easier for the enzyme to work on
Small intestine
6 meters (18ft) long. 5 hours to be processed and digested here
Duodenum, Jejunum, Ileum
Villi
In small intestine to increase SA for absorption and digestion
Duodenum
First part of Small intestine
Mix with bile from gallbladder and digestive juice from pancreas
HCO3- raises pH to aorund 6.5
Bile
Made in liver, stored in gallbladder
Helps with digestion, absorption of fats via emulsifying, excretion
Composed of bile salts, phospholipids, cholesterol, bilirubin
Pancreas
Helps break down food, control blood sugar, tell your stomach when to empty, etc.
Release pancreatic lipase and pancreatic amylase
Jejunum
Absorb sugars, AA, and FA
Ileum
Absorb any remaining nutrients that did not get absorbed by duodenum or jejunum
Type of transport for the main molecules
Active transport: Glucose, AA
Facilitated diffusion (active): Monosaccharides
Simple diffusion: triglycerides
Osmosis: Water
Trypsin
AA cleaving enzyme in SI
Has zymogen (trypsinogen)
Can cause pancreatitis if not regulated
Nucleotide breakdown
Broken down by nucleases and are absorbed by active transport
We uses their sugar residues
Vitamin/mineral absorption
Mostly absorbed in ilium
Ca2+ can be actively or passively (osmosis) transported into blood. Supplementation promotes passive
Large intestine
~ 5 feet long
10 hours to several days for processing with average 36 hours. Full of bacteria
Absorbs water via osmosis and the aid of mechanical contractions which also push electrolytes into the blood
Chyme
Semi-fluid mass of partly digested food that is left after the SI
Bifidobacteria
Help modulate immune response, regulate other gut bacteria, prevent tumor formation, produce vitamins
Escherichia coli (E Coli)
Help produce vitamin K2, keep bad bacteria in check. Some strains can cause disease
Lactobacilli
Produce vitamins and nutrients, boost immunity, protect against carcinogens
Campylobacter
(Food poisoning) C. Coli and C. Jejunii most commonly associated with human disease. Ingested through contaminated food
Clostridium difficile
Dangerous when it proliferates following a course of antibiotics
Enterococcus Faecalis
Common cause of post-surgical infections
Gas formation
Air can be ingested through esophagus
Non-digestible carbs are broken down without O2 and ferment –> produce gas
Homeostasis
Maintain stable internal environment, even when external environment changes
Factors that must remain stable for homeostasis
Temperature, blood pH, water levels, blood glucose
Insulin
Released by pancreas when glucose increases in the blood. The “key” that unlocks the glucose channel
Glucagon
Released by pancreas when low blood sugar and stimulates glycogen breakdown
Type 1 diabetes
Genetic autoimmune disease
Immune system confuses insulin producing cells in pancreas for a threat so it destroys them
Type 2 diabetes
Genetic and environmental factors
Pancreas produces too much insulin the receptors stop functioning or don’t recognize the insulin anymore
Caused by stressful and/or sedentary lifestyle
“troph”
Nourishment or simply food
See flow chart on slide 219
Hetero
Fuel from different organic substance
Auto
Fuel from inorganic substance
Chemo
Fuel from organic substance with some exceptions like sulfur and iron
Photo
Fuel via light
Types of herotrophic nutrition
Saprotrophic, parasitic, holozoic
Saprotrophic nutrition
Eat dead plants, dead & decaying animal bodies
ex: yeast, mushrooms
Parasitic nutrition
Feeds on another actively living organism
ex: tapeworm or lice
Holozoic nutriton
Ingestion of organic food materials
ex: human beings, ameoba
Need a mouth
4 classifications of Holozoic
Herbivores, carnivores, omnivores, detritivores
Herbivores
Eat autotrophs, specialized digestive tracts to breakdown cellulose
Cecum digests cellulose via special bacteria and enzymes
Longer SI and sometimes multiple stomachs
In direct competition with us because they eat our food (crops)
ex: Cows, parrots, honeybees
Carnivores
Eat other heterotrophs
Require a lot of energy to maintain metabolism
ex: lion, shark , polar bears, frogs
Omnivores
Eat other heterotrophs and autotrophs
In every animal kingdom and in protists
ex: humans, bears, pigs, wasps
Detritivores
Eat dead and decaying things
ex: bacterias, earthworms, fungi
Protostomes
a classification of animals by the fact that their mouth developed first
Most protostomes are insects
Insects digestion
Stomach pH ~6.5-7
Contain relatively few microbial species compared to mammals, some specialized bacteria, organs aren’t as separate as ours
Spiracles
Holes which open to environment and are connected to air tubules in insects
Insects quiver to breath and push air into these holes
Deuterostomes
Anus first development
Mammals
Backward development from protostomes and relates to such animal diversity
Complex respiratory system and high energy demand
Bacteria and fungi (general, examples)
Herbivores, can be carnivores
Pseudomonas syringe = bacteria model organism
Botrytis Cinerea = Fungi infect grapes
Phytophthora infestans = protist (potato blight)
Amoebas
Protists
Single cell carnivores that eat via phagocytosis
Photoheterotrophs
Gain energy from the sun but must eat a carbon source
Most are bacteria, common in ocean
Ex: oriental hornet, paramecium
Lithotrophs
(stone eater) Chemoheterotrophs that eat inorganic substances (rocks) for carbon sources
Ex: Sulfur bacteria, metallosphaera sedula
Saprotrophs
Eat dead, decomposing tissue
ex: Fungi
Fungi
Spore, mycelium, fruitbody
Grow in circles
Mycelium
Release enzymes into the environment to breakdown nutrients from dead tissue and then absorb them (aka digest outside of body)
Transport broken down organic back into cell
Will grow until out of nutrients (sometimes thousands of years)
What can fungi breakdown specially
Lignin (wood)
First and most common organism to do this
Great implications on carbon source ecosystems
Parasitism
Symbiotic relationship which one organism benefits while the other is harmed (heterotrophs that hurt host)
Complex life cycles that cause them to change hosts
Everyone has had a parasite but typically dealt with by immune system before deadly
ex: tick and dog, hookworm and human etc., mistletoe to plant
How to avoid parasites
Wear gloves when gardening or cleaning litter boxes, fully cook meat, wash fruit and veggies
Autotroph
Make their own macromolecules for nutrition
Producers of ecosystem
Most animals depend on them to survive
Largest, long-lived organisms
Chemosynthesis
create useable energy WITHOUT light
ex: deep in ocean, thermal vents provided sulfur and carbon to deep sea creature (fist life)
Photosynthesis
Create usable energy using light
Mutualism
Both species benefit from the symbiosis
ex: humans and gut bacteria
Commensalism
One species benefits, the other is unaffected by the symbiosis
ex: cattle egret and cattle
Mycorrhizae
Mutualistic alliance of plant with fungi
(both benefit)
Plants call fungus near their roots via chemical release which promotes bacteria growth near plant
Fungi and plant can exchange nutrients
Likely the reason for plants and animals living on land
Who proposed endosymbiotic theory
Konstantin Mereschkowski
Endosymbiotic theory
Organelles that distinguish eukaryotes and prokaryotes emerged through mutually beneficial relationship between individual prokaryotes
Engulf of one prokaryote by the other gave rise to mitochondria and chloroplasts
See slide 260
Evidence for endosymbiotic theory
MADDR
Membranes: Double membrane
Antibiotics: susceptible to antibiotics aka bacterial origin
Division: Reproduction occurs via fission
DNA: Own, naked circular DNA
Ribosomes: Ribosomes identical size to prokaryotic
How do plants have mitochondria and chloroplasts
They had 2 endosymbiotic events in their history
Mitochon and chloroplast DNA past on via mother because sperm sacrifices to give up DNA
Where does virtually all energy come from
SUN
Coal
Organic material from ancient plants
Wind
from the sun warming one side of the planet and not the other
Hydropower
From the sun evaporating water which falls on higher elevations
Food
Most food chains start with energy from a photosynthetic organism
Every carbon in your body has gone through photosynthesis
Air from plants
We breath oxygen from photosynth
60% O2 from plants
40% from photosynthetic ocean life
Stomata
Plant “mouth” to breath
CO2 enters via passive diffusion
Opening is controlled via water pressure and light
Lose water in vapor and “exhale” O2
Plant cell unique characteristics
Cell wall, rigid, large central vacuole , chloroplasts, lack centrosomes, lack lysosomes
Animal cell unique characteristics
No cell wall, flexible, numerous small vacuoles, no chloroplasts, centrioles/centrosomes, lysosomes
Proplastid
Stem cells that turn into all the other plasts such as chloroplasts, elaioplast, etioplast, amyloplast, cromoplast
Structures of chloroplast
See slide 270
Granum
Thylakoid
stroma inner and outer mem.
Stroma lamellae
Thylakoid
Disc where photosynthesis occurs stacks of these create granum
Rxn of photosynth
6H2O + 6CO2 –> C6H12O6 + 6O2
Endergonic reaction
Why is photosynth reaction not like other reactions
Because H2O and CO2 don’t interact at all.
H2O is electron donor that gets oxidized to produce O2
In separate reactions CO2 is e- acceptor making G3P which combines to make glucose
RXNs are coupled to make glucose but kept separate
Light side
Water oxidized to make ATP and O2
Dark side
CO2 uses ATP from light side and makes G3P
Light rxns
Occur in thylakoid membrane
light + water = ATP + NADPH and byproduct of O2
Light as a wave
Larger wavelength = less energy
Our eyes see 380-760 nm
Plants absorb energy from some of these wavelengths
Chlorophyll
Plant pigment, light absorber
Types a and b
Electrons are highly mobile in light absorbing region
Hydrocarbon tail that extends into thylakoid membrane to anchor chlorophyll
See structure on 277
Photon
Packet of light energy
Absorbed by the plant to elevate electron from ground state to excited
Must be specific wavelength to dislodge e- and make it jump to higher level
How chlorophyll uses photon energy
Harvests excited electrons and use them to create ATP and NADPH
Lost light at lower energy level and will change color (release light of a larger wavelength, lower frequency)
Wavelengths chlorophyll B absorbs
Blue (smaller wavelength)
Wavelengths chlorophyll A absorbs
Orange and red
Longer wavelengths
Why does chlorophyll look green
green light is not absorbed by it and therefore is reflected and that is why we see it
How do plants trap energy
energy from excited electron gets transferred from one chlorophyll to another via resonance energy transfer (down a staircase) until it reaches the reaction center where e- is removed from chlorophyll and passed to primary e- acceptor
Photosystem
“Mouth” where energy transfer begins
2 of them
Photosystem II comes first but was discovered second
ETC of stroma
Walk through slides 285-290
Series of redox reactions where electron is dropping energy as it moves through
Pq oxidized then Cyt then Pc
When reduced they grab a proton when oxidized releases proton to lumen
End of ETC
e- get transferred to a new molecule of chlorophyll replacing a previously removed e-
e- get another energy boost from PSI and energy is stored in NADPH
How ATP is made
Proton gradient in thylakoid membrane created by ETC flow down their CG to power ATP synthase
Photophosphorylation
ADP –> ATP is NOT a redox reaction
It is endergonic but is powered by [H+] gradient
Summary EQ of light reactions
12 H2O + 12 NADP+ + 18 ADP + 18Pi + light —> 6O2 + 12 NADPH + 18 ATP
What is water used for in PSII
Split H2O to replace the energy that is lost with the electron that gets stripped from chlorophyll
2 waters needed to make one O2
What is missing from products of light rxns that is needed to make glucose
CO2
Phases of the Calvin Cycle
CRCR
Carbon fixation
Reduction
Carbohydrate formation
Regeneration
Where does the Calvin cycle take place
stroma of the chloroplasts
Who and how discovered calvin cycle
Melvin Calvin did via tracking radioactive carbon 14
Calvin cycle process
Go over steps slide 303
Regenerates molecules needed for light reactions
Carbon fixation
CO2 combined with RuBP ad fixed into organic 6 carbon molecule that is split into 2 3PGA (low PE)
Reduction
Uses ATP and NADPH (anabolic) the 2 3PGA molecules are converted into G3P (higher PE than 3PGA)
Carbohydrate formation
2 G3P is taken out of chloroplast and converted into glucose (or other sugars)
Regeneration
10 G3P and 6 ATP used to regenerate RuBP
“Carbon shuffle”
Very energy INefficient
Rubisco
Eight catalytic sites where it takes Carbon from CO2 and adds it to RuBP and then splits it in half
Most abundant enzyme on the planet
Slow and huge
Also like O2 which is a problem
Summary of calvin cycle
6CO2 + 12 NADPH + 6 H2O + 18 ATP –> 2 G3P + 12 H + 12 NADP+ + 18 ADP + 18 Pi
Fate of G3P
To the cytosol where it can be made into glucose for CR in mitochon, made into cellulose, sucrose to be transported to different part of plant
Can be used to make EVERY other macromolecule (FA, AA, starch, etc)
