BIO 012 Lecture Notes - Lecture 16: Cellular Respiration, Overnutrition, Calorie
12 Jun 2018
School
Department
Course
Professor
Chapter 51: Nutrition, Digestion
51.1 What do Animals Require from Food?
Animals are heterotrophs – they derive their nutrition from eating other organisms whereas, autotrophs
can use solar energy or inorganic chemical energy to synthesize all of their components.
Why do we eat?
- We get energy from food.
- 1st law of thermodynamics: energy cannot be created or destroyed. Only can be converted
from one form to another.
- A aial’s eerg eeds ust e et the igestio, digestio, ad assiilatio of food.
What is the energy in food used for?
- Homeostasis
- Cellular respiration – ATP
- Metabolism
Measuring this energy
- Calorie: the amount of heat needed to raise the temperature of 1 gram of water by 1 degree
Celsius.
- 1 kcal = 1000 calories
- Calorie = 1 kcal: calories listed on nutrition labels are actually kcals. So, 30 cal = 30,000 kcal
Energy Budgets
- Calories consumed vs. calories expended
o Calories expended is based on the energy demands of the body – sitting at a chair for
hours is low demand vs. going to the gym which is a high demand
- Energy budget for the day: Breakfast should be the largest meal of the day in order to give
you fuel to get through the whole day; lunch should be smaller because by then we would
have less of the day to get through; dinner should be the smallest because you only have to
survive a small amount of time
- Overnutrition: energy intake is greater than energy expended
o Some wild animals get a little fatter like in the time before hibernation.
▪ Ex: bears, sometimes squirrels, and even us too
Energy Stores
- Store type depends on the demands
Level 1: ATP has high energy bonds between the 2nd and 3rd phosphate groups
- Not er stale; that h ou a’t keep ATP i the log ter
- Can have it move in short distances but it is used quick.
Level 2: Glucose (monosaccharides) – sugars and carbohydrates, and glycogen (polysaccharides)
- Sugars and carbs have just one ring structure: carbons attached to hydrogens
- Storing glucose for longer periods of time → attaching them to other glucoses makes glycogen
find more resources at oneclass.com
find more resources at oneclass.com
o More efficient because of osmosis (movement of water based on number of
molecules)
▪ Single glucose molecules take water and suck it out of the blood
▪ Glycogen draws less water to each glycogen molecule: easier to save water
for a long period of time
Level 3: Fat – very high energy storage molecule; very stable; can save for longer
Level 4: Protein – etreel stale, od does’t like to use protei uless it ust, ould rather use it for
things it needs it for suh as protei eraes. If it’s all that is left, the the od ill use it. It’s a last
resort. Malourished people do’t hae usle eause the do’t hae protei.
- People ho follo the Atki’s diet; eliiate ars fro diet so the od uses protein instead.
This is bad because you start making metabolic waste. You have shocked your system, so you
will lose weight, but then you start to adjust and will put weight back on.
Order of fuel use in starvation
- Edema – fluid starts being pulled from
tissues, so the stomach area begins to swell
like in malnourished and starving children.
Essential Molecules
- Acetyl Group: (CH3CO-) building block that supplies the carbon skeleton; come from the foods
you eat; 2 carbons bonded together; Needed to make steroid hormones
find more resources at oneclass.com
find more resources at oneclass.com
Essential Amino Acids for Building Proteins
- Many times, we break down food to the building blocks, so we can build the proteins we need
- The uildig loks that e a’t ake are alled essetial → we need to ingest them, and
they are essential for our diets
- 8 essential amino acids for adult humans: Tryptophan (in turkey), Methionine, Valine,
Threonine, Phenylalanine, Leucine, Isoleucine, Lysine
o E: egetarias do’t get these easil; hips (grains in tortilla chip) and beans in bean
dip gives them
Why not use pre-made proteins from food we eat?
- Marooleules a’t e asored as effiietl as the saller aio aid uildig loks
- Protein structure and function are species specific
o We can break down the food to get building blocks and make the proteins that we
need compared to other animals
- Immune System → based on proteins that are made in your body
o The immune system will attack proteins that enter the body so they need to be
broken down through digestion so that they can be remade into the proteins the body
eeds ad therefore the iue sste o’t pai ad attak the.
Vitamins and Minerals
- Minerals – macronutrients like calcium (needed in large quantities); and micronutrients like
iron (needed in small amounts)
- Vitamins
o Carbon compounds that an animal require for growth and metabolism
o Essential vitamins vary from species to species
o Water soluble, fat soluble, and excess vitamins
Nutrient deficiencies result in diseases
- The lack of any nutrient is malnutrition and chronic malnutrition can lead to deficiency
disease.
- Deficiency diseases can also result from an inability to absorb or process an essential nutrient
even if it is present in the diet.
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Animals are heterotrophs they derive their nutrition from eating other organisms whereas, autotrophs can use solar energy or inorganic chemical energy to synthesize all of their components. 1st law of thermodynamics: energy cannot be created or destroyed. Only can be converted from one form to another. A(cid:374) a(cid:374)i(cid:373)al"s e(cid:374)erg(cid:455) (cid:374)eeds (cid:373)ust (cid:271)e (cid:373)et (cid:271)(cid:455) the i(cid:374)gestio(cid:374), digestio(cid:374), a(cid:374)d assi(cid:373)ilatio(cid:374) of food. Calorie: the amount of heat needed to raise the temperature of 1 gram of water by 1 degree. Calorie = 1 kcal: calories listed on nutrition labels are actually kcals. Calories consumed vs. calories expended: calories expended is based on the energy demands of the body sitting at a chair for hours is low demand vs. going to the gym which is a high demand. Overnutrition: energy intake is greater than energy expended: some wild animals get a little fatter like in the time before hibernation, ex: bears, sometimes squirrels, and even us too.
