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Need food as fuel for cellular work
Organic and raw materials for biosynthesis
Essential nutrients like vitamins that an animal can’t make itself
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Carb is a fancy word for sugar
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Used for functions
Carbs
Fats
Protein
Vitamins
Minerals
Water
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The rest is waste
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Herbivores
○ Only plants
Carnivores
○ Only meat
Omnivores
○ Both
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Calories
The measure of energy from food
The temp required to raise 1 gram of water by 1 degree Celsius
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BMR
Around 70 calories per person
Person weighing 120 pounds needs between 1800-2400 (1400 to live)
Person weighing 160 pounds (1700 minimum) 2400-3200 to thrive
People need 50-100% more calories per day than your BMR (Basal metabolic rate)
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Water is 60-65% of body weight
2-3 liters are needed per day
Water lost through respiration, defecation, sweating, urine
Need water for intracellular fluid and blood
Can lose around 25% of your water before you die
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Protein
Come from food, meat and plant
Comprised of amnio acids, which are the cellular workers
Need protein regularly, can’t rely on storage
If you overeat it, stored as fat
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Incomplete proteins don’t have all amino acids
Complete have all 8
Only soybeans have all 8
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There are 20 amino acids that all animals have, around half comes from molecules in
diet
The rest of amino acids must be obtained from food
Meat, eggs, cheese provide al the essential amino aicds and are thus complete proteins
Most proteins are incomplete
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Carbs
Sugars are used for energy
From fruits and grains
Stored in the liver and muscle cells as glycogen for about a day then are used for energy
Can be stored as fat
Sugar is the primary input for ATP production
Includes
Simple sugars
○ Quickest ATP
Digestible complex sugars
○ Takes longer to break down
○ Chops off sugar to put in bloodstream
Fiber
○ Helps things move through the body, isn’t used
○ Slows down the digestion of other things
Fats
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Primary use is for long term energy storage
Is not typically used to make ATP
Fat provides lots of calories per gram
The ability to store fat was a good genetic trait
Saturated Fats
○ Unhealthy fats
○ Solid at room temperature
○ Structure of molecules are straight, can get packed together more
○ More likely to be stored as fat in the body
Unsaturated Fats
○ Healthy
○ Looser tail, can’t be packed as tightly together
○ Less likely to be stored as fat in the body
○ Tends to be liquid at room temperature, easier for the body to use these fats
○ Most plant fats
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Trans fat
○ Fat used to be demonized, fat free products were sold
○ Trans-Fat is mostly human created
○ Takes an unsaturated fat and add a hydrogen
○ This will straighten out the carbon chain
○ Lets them be shelf stable for a longer period of time
○ Worse than saturated fats because your body hasn’t seen it before, doesn’t know
how to use it, more likely to be stored as fat and increase cholesterol
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Essential Fatty Acids
○ Animals can synthesize most of the fatty acids they need
○ Essential fatty acids are certain fatty acids that must be obtained from the diet
○ Omega-3 and omega-6
○ Deficiencies in fatty acids are rare,
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Excess calories are stored as fat in the body
One pound of body fat stores around 3,6000 Kcal of energy
So to lose one pound technically you have to burn 3,600 more calories than you
consume
Carbs are burned before fat
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To break down complex carbs
○ Energy is used to break down complex sugars
○ Energy is used to break down simple sugars
○ Energy is used to reassemble fragments into fatty acids
○ Fatty acid is stored as fat
○ This process takes lots of energy so it is less likely to be stored as fat
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Fats carry the most energy per unit
Carbs are quick, fats are long
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Vitamins
○ Most are essential and need to be gotten from the environment
○ Vitamin D is in the skin, needs sun
○ Most vitamins are co-enzymes. Cells need them to go through a process
○ Scurvy comes from a vitamin C deficiency (Loss of teeth, sunken eyes, pale skin)
Minerals
○ Calcium
○ Iron
○ Iron deficiency: Anemia, fatigue, weakness
○ Iodine Deficiency: Enlargement of thyroid gland
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Undernourishment
A diet that is missing chemical energy
Undernourished people will
○ Use of fat and carbs
○ Break down proteins
○ Lose muscle mass
○ Suffer protein deficiency of the brain
○ Die or suffer irreversible damage
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Malnourishment
○ Long-term absence of a part of the diet
○ Can cause deformities, disease, death
○ Can be correct
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Dietary supplements aren’t necessarily helpful
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Types of Muscle
Skeletal
○ Moved by the nervous system
○ Two opposing muscles on either side of the bones, allow you to contract and
relax in different directions
○ Muscle Contractions
○ The action potential is sent through a motor neuron
○ Motor neuron attaches to the muscle fiber
○ Acetylcholine gets released
○ Acetylcholine causes a depolarization of the muscle itself causing an action
potential
○ Muscle cells have a nucleus with DNA, has various nuclei: makes it easier to
make more proteins
○ Muscle Fiber is a muscle cell
○ Has multiple nuclei with numerous myofibrils
○ Sarcomeres are composed of large numbers of long filaments made from
proteins actin and myosin
Muscle Contraction
○ See the powerpoint
○ Link between myosin and actin filaments
○ ATP is the energy currency of our body
○ Calcium is released because of the action potential
○ When a muscle is at rest it cant find on to actin
○ For a muscle cell to contract, myosin-binding sites must be uncovered
Cardiac
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Smooth
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Digestive tract, involuntary
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Oxidated Fibers slow twitch
○ Rely on Aeorobic respiration to generate ATP
○ Fibers have many mitochondria, a rich blood source, hemoglobin
○ Myoglobin is a protein that binds oxygen more tightly than hemoglobin does
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Most skeletal muscle contain both fast and slow twitch in varying ratios
Slow-twitch contract more slowly
Aerobic
Fast twitch
○ Anaerobic or aerobic, fast and short
○ Less ability to use ATP for energy
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How do muscle cells grow
○ Can add nuclei to the muscle cell itself
○ More nuclei increases muscle protein synthesis
○ More androgen means easier muscle growth
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Muscle Disorders
○ ALS, interferes with the excitation of skeletal muscle fibers, this disease is usually
fatal
○ Myasthenia Gravis
○ Attacks acetylcholine receptors on muscle fibers, causing muscle weakness
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Skeletal muscle
○ Striated
○ Actin and Myosin create the stripe appearance
○ Myosin uses ATP for energy and attaches to Actin cuz of Calcium when it is
present
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Cardiac Muscle
○ Similar organization of Actin and Myoson
○ Single nucleus
○ Involuntary contraction
○ Intercalculated Discs
○ Action potential in once cell can flow to the next
○ If you don’t have enough oxygen to the heart, the cells will stop functioning (Heart
attack)
○ Designed for aerobic respiration
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Smooth muscle
○ No striations
○ Contains actin and myosin
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Loosely arranged filaments, poorly understood
Stomach, intestines, arteries
Slow, sustaind contractions
Single nucleus
Involuntary
Ecology
○ Organism interaction with environment
○ Population ecology: study of populations of organisms of a species and how they
interact with the environment
○ Group of organisms of the same species in a specific area
Ecosystem
○ Community of biological organisms plus the non living components with which
they interact
○ Nutrients are consistently recycled through the ecosystem
○ How energy moves through the community
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Energy flow within an ecosystem
○ Primary producers
○ Plants convert sun into energy, make their own food
○ Primary Consumers
○ Herbivores are animals that eat plants
○ Eat plants
○ Secondary Consumers
○ Carnivores, omnivores, can eat plant and other animals
○ Tertiary consumers
○ Top predator
○ Eating larger animals
○ Final level is decomposers
○ Eat and break down dead material. These feed the soil and plants
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You use most of the calories you intake to do tasks, the rest if left over to get larger
Going from one trophic level to another is roughly 10%
Energy is expended during cellular respiration or feces
More efficient to eat plant material than to eat the animal that ate the plant
material’
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Need less food if your eating the omnivore shit first
This is why it contributes to waste and global warming
Tuna build up lots of mercury and it can be dangerous for us to eat it
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Nutrient Cycles
○ Resevoirs of where a nutrient comes from
○ Major resevoirs are usually in the abiotic parts of the environment
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Nutrients move through water
Goes into the atmosphere, taken back down
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Carbon is stored in the atmosphere as carbon dioxide
○ Carbon is the main part of most molecules
○ Break down ATP, breath out carbon dioxide
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Short quick energy has fewer mitochondria, (Where ATP is made)
Slow twitch needs more ATP
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Water is needed as part of the nutrients that are essential, protein and amino acids are
the same
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Primary pro
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Carbon Cycle
○ Plants use carbon molecules from the atmosphereand light energy from the sun
to make photosynthesis
○ Carbon moves through the food chain as plants and organisms are eaten,
organisms get energy from carbon bonds and breath out carbon dioxide
○ When large numbers of organisms die, carbon accumulates on hte ground, over
time the organic remains can be transformed into coal, oil, and gas
○ Burning coal oil and gas releases carbon dioxide into the air
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Carbon dioxide fluctuates over time
Has been much more exaggerated recently
Global warming rises when carbon dioxide goes up, this is a greenhouse gas
○ Carbon dioxide acts like the glass around the greenhouse, heating up the
earth
○ Average temperature would be below zero without carbon dioxide trapping heat
○ When it traps too much heat, it can overheat the earth
○ Ocean levels rise with melting sea ice
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There is a debate whether these chars are a natural part of the cycle, or if humans are
expediting the process
This is measure with prediction graphs versus actualy graphs
Trees and flowers, migratory birds, bird and butterflies are all showing the effects
of climate change. Their cycles are messed up
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Nitrogen Cycle
○ Nitrogen gas has a structure that is unusable by most organisms, but bacteria
that live in the soil can convert the nitrogen gas into things usable by plants
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Nitrogen compounds can be modified by other bacteria into the form that can be
taken by plants and used as protein
Nitrogen moves through the food chain as organisms and plants get eaten
Animal wastes are broken down by soil bacteria and converted into nitrogen
tissue, returned back into the atmosphere
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Plants need nitrogen to grow
Burning fossil fuels combines atmospheric nitrogen and oxygen to be used by plants
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Water dissolves and carries large quantities of fertilizers into lakes and overstimulates
the growth of plankton
Nothing survives in dead zones because sewage and fertilizer get eaten by algae
Major farms in the middle of country, put tons of fertilizer, creates dead zone in
mississippi
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Phosphorus cycle
○ Plants absorb phosphate into themselves
○ Create ATP, passed through the food chain
○ Returns to soil when animals die
○ When rocks get weathered, more phosphate will get released into the soil
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Eutrophication, too much use of fertilizer, rapid growth of algae, oxygen gets
consumed, animals die
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ACID Rain
○ When atmospheric nitrogen and 75% of sulfur are produced from burning fossil
fuels
○ Two substances combined with water and nitric and sulfuric acids
○ Excess production of these two substances leads to acid deposition or acid rain
○ Trees are damaged by acid rain
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Biodiversity
○ Biodiversity benefits humans
○ Random small plants help us create drugs
○ Cancer drug called taxol comes from a tree that grows in the Pacific NW
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Utilitarian Value
Aesthetic Value
Symbolic Value
Naturalistic Value’
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We're in the middle of a mass extinction
○ Most dinosaurs died from the asteroid, but birds and small animals were able to
○ When global warming happens most species on earth will die
○ 40% of amphibians are extinct, 25% of mammals (75% of pop died)
○ Large amounts are endangered
○ Hunting, habitat loss are another big reason
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Human interference generally reduces biodiversity
○ We use 3or4 times more resources than the earth can provide
○ Once lost, a species can’t be recreated
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Introduction of Exotic Species to certain area messes with ecosystems
○ Invasive species can out-compete the native species
○ Monk Parakeets make massive nests in Chicago powerlines
○ Plants, snakes, mussels all disrupt their ecosystems
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Some products have ozone-depleting CFC’s
○ This gets into the air, they form compounds that break down the ozone
○ Ozone protects the earth from UV light
○ The more UV light increases illness in aimals nad lower photosyntehsis
○ CFCs leak into the atmoshpere where they break down the Ozone
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Deforestation of tropical rainforests
○ Fast clearing endangers species, increases concentration of greenhouse gases
○ Agriculture, gold mines, oil wells are created
○ Biodiversity is highest in the rainforests
○ Plants and trees removes CO2 from the atmospheres because they breath
it in and turn it into oxygen
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What should we protect in terms of species?
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Landscape conservation
○ Yosemite is preserved as a national park
○ Making sure animals are not cut off from each other
○ Need gene flow
○ Corridors would allow species to stay interconnected
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Nutrition
○ Types of nutrients
○ Metabolic rate, at rest and moving
○ Deficiencies, Iron and
○ Digestion
○ Alternative digestive systems, example
○ Glucose insulin
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Muscles
○ Three types
○ Skeletal muscle, how it contracts in detain
○ Fast and slow twitch
○ Cardiac and smooth, how they differ
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Energy flow
○ How energy is lost and moves through trophic levels
○ Biological magnification
○ Carbon, nitrogen, phosphorus cycles
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Biodiversity
○ Mass extinction