KIN 3515 - Exam 2 - Bioenergetics and Exercise Metabolism - Spielmann

3 Macronutrients

Carbohydrates

Lipids

Protein

Calorie

amount of energy required to raise 1 gram of water by 1 degree

How many calories are in 1 kcal

1000 calories

Direct calorimetry

direct measurement of heat release from food

Bomb Calorimeter

measures the amount of calories in food

The bomb calorimeter is surrounded by _____?

water

Indirect calorimetry

measures oxygen utilization that relates to heat production

How many kcal/g does a carbohydrate have?

4.2 kcal/g

How much kcal/g does a lipid have?

9.4 kcal/g

How much kcal/g does a protein have?

5.65 kcal/g

Atwater Values

provides a useful estimate of the net energy value of typical foods a person consumes

Average Atwater value for carbohydrates

4 kcal/g

Average Atwater value for lipids

9 kcal/g

Average Atwater value for proteins

4 kcal/g

Average Atwater value for alcohols

7 kcal/g

What is the basic unit for a carbohydrate?

Monosaccharides

Monosaccharides form _____ for storage in the liver and muscle

Glycogen

Monosaccharides can convert to _____ for later energy use

fat

3 major monosaccharides

Glucose or dextrose (blood sugar)

Fructose (fruit sugar)

Galactose (milk sugar)

What are 2-10 monosaccharides bonded chemically called?

Oligosaccharides

3 major oligosaccharides

Maltose = glucose + glucose

Lactose = glucose + galactose

Sucrose = glucose + fructose

Maltose is found in?

Breakfast cereals, beer, and seeds

Lactose is found only in?

Milk

Sucrose is found in?

Table sugar, brown sugar, maple syrup, honey

Polysaccharides

3 to thousands of monosaccharide molecule linkages

Example of polysaccharides

Starch (plants)

Glycogen (animals and humans)

Glucogenesis

glycogen synthesis from glucose

Glucose --> glycogen

Gluconeogenesis

glucose synthesis from non-carbohydrate nutrients

Protein --> glucose

Why is gluconeogenesis important?

Necessary for brain to function

Glycogenolysis

glucose formation from glycogen

(Glycogen --> glucose)

Why do you need to break down glycogen?

To help maintain blood glucose levels

Where is glycogen stored?

Muscle and liver

What is the carbohydrate's role in the body?

Energy source during intense exercise

What should you do to maintain blood glucose levels?

Drink and eat carbohydrates

Carbohydrates serves a as

Primer for fat oxidation

For moderate and prolonged exercise, what is used?

Fats (fatty acid)

A low carbohydrate diet, tends to ______ performance during prolonged exercise

Decrease

The net energy provided by oxidation of protein is ___ - ____ kcal/gram

3.8-4.2 kcal/gram

What are the three lipid groups?

Simple: triglycerides/triacylglycerols

Compound: phospholipids

Derived: cholesterol

What is the importance of cholesterol?

Helps synthesize estrogen and testosterone

Major storage form of fat

Adipocytes (fat cells)

Triacylglycerol Formation (esterification)

Fatty Acid binds to Coenzyme A to form Fatty Acyl-CoA which then turns to glycerol (G-3-P)

Does triacylglycerol synthesis increase or decrease following a meal?

Increase

Why does triacylglycerol synthesis increase after a meal?

-Food absorption increases fatty acids and glucose

-High levels of insulin facilitate triacylglycerol synthesis

Insulin is a __________ ___________

storage hormone

Insulin synthesizes

triglycerides

Insulin stimulates

enzymes to increase fatty acid (FA) storage

Lipolysis

breakdown of fats

Lipolysis occurs

- during low-to-moderate intensity activity

- during fasting or low calorie dieting

-Prolonged exercise that depletes glycogen reserve

Hydrolysis

breaks down FA by adding water

High-Density Lipoprotein (HDL)

"good" cholesterol

helps reverse cholesterol transport and transport it back to the liver so it can be processed properly

Low-Density Lipoprotein (LDL)

"Bad" cholesterol

Can cause plaque build up and heart disease

Very low-density lipoprotein (VLDL)

transport triacylglycerides (TAGs) to muscles and adipose tissues

Does cholesterol contain fatty acids?

No

Major functions of lipids

-Energy source and reserve

-Protect vital organs

-Thermal insulation

-Vitamin carrier and hunger suppressor

Which is more storage efficient?

Fat --> has more kcal/gram

Which is more metabolic efficient?

Carbohydrates --> kcal/liter

Why do you want to oxidize carbohydrates instead of fats?

Get more energy

What source of energy is used for high-intensity exercise?

Carbohydrates

What source of energy is used for low-intensity exercise?

Fats

Unlike carbohydrates and lipids, proteins have approx. 16% of?

Nitrogen

Does proteins give us any energy when we oxidize it?

No

4 common features of all amino acids

-R-group or side chain

-Central hydrocarbon group

-NH2 (amine group)

-COOH (carboxyl) group

Essential Amino Acids

body cannot synthesize them so they have to consumed in foods

Nonessential Amino Acids

body can synthesize from other compounds

Complete proteins

exist in foods that contain all the essential amino acids

Incomplete proteins

lack one or more essential amino acids

Deamination

Nitrogen removal

Forms urea

Transamination

transfer amine to create a new amine group

What is the major metabolic pathway for amino acids?

TCA cycle

Do athletes require the same amount of protein intake per kg of body weight compared to non-athletes? True or False

False

Work =

Force * Distance

Measured in joules (J)

1st Law of Thermodynamics

Energy cannot be created or destroyed, only transformed from one form to another

System Total Energy =

Potential energy + kinetic energy

Kinetic Energy

relates to energy of motion with release of heat

Biosynthesis

put things together to make them more complex

ex. glycogen: made of glucose

Exergonic

releases energy to surroundings ("downhill" process)

Example of exergonic

glycogen --> glucose

Endergonic

Stores or absorbs energy

Example of endergonic

glucose --> glycogen

Is there more energy in glycogen than glucose? If so, why?

Yes, because there are thousands of glucose molecules

Are endergonic and exergonic reactions coupled together?

Yes, because exergonic reactions provide the energy for endergonic reactions

_______ _________ is a form of potential energy stored in ________ ________

Chemical energy; covalent bonds

What are the 3 most important forms of energy for humans?

Chemical, Mechanical, and Heat

Photosynthesis is an example of which energy process?

Endergonic

Respiration is an example of which energy process?

Exergonic

Enzyme

Lowers activation energy barrier of reaction

Coenzymes

Facilitate enzyme action by binding a substrate to its specific enzyme

Do temperature and pH affect enzymes?

Yes

When we workout _____ goes down and causes muscles to fatigue.

pH

Noncompetitive Inhibitors

-bind to enzyme's active site to prevent enzyme activation

- slows the reaction rate down

Hydrolysis: catabolism or anabolism?

Catabolism

Condensation: catabolism or anabolism?

Anabolism

Oxidation

loss of electrons

Reduction

gain of electrons

Oxidation is also known as a _____ agent

reducing

Reduction is also known as ______ agent

oxidizing

_____ is the breakdown of complex molecules to less complex molecules, that releases ________

Catabolism; heat and free energy

Electron Transport System

transport of electrons by specific carrier molecules

Do we have a lot of ATP stored?

No, we need to continuously make ATP