Energy Transfer in the Body

Question 1

What is “biosynthesis”?

Answer 1

The human body transforms energy from one state into another (can not be “destroyed”)

–> Food energy: the total energy value of macronutrients
- Carbs: 4 kcal/gram
- Proteins: 4 kcal/g
- Lipids: 9 kcal/g

–> Atoms of carbon, hydrogen oxygen, and nitrogen from macronutrients become activated and join other atoms and molecules to synthesize important biologic compounds and tissues

Question 1

What is “bioenergetics”?

Answer 1

The flow and exchange of energy within a living system

• The 1st law of thermodynamics

Question 2

All potential energy in biological systems degrades to the unusable from of kinetic energy (heat) and is made possible with the help of enzymes and co-enzymes.

Question 3

What are “enzymes”?

Answer 3

Highly specific substance which acts as a catalyst to bring about a specific biochemical reaction

–> Accelerates the forward and reverse of chemical reactions without themselves being consumed or changed during the reaction

–> Enzyme activity can increase 100x resting level when energy demands rise

 - large capacity to increase its 
   rate 
 - rate limiting in the transfer of 
   chemical energy to mechanical 
   work 
 - make or break or rate limit on 
   how much ATP can be 
   generated

Question 4

What are “coenzymes”?

Answer 4

Nonprotein organic substances that facilitate enzyme action by binding the substrate with a specific enzyme

–> Some enzymes will remain dormant until activated by coenzymes

Question 5

What are the 3 types of work that we take food energy and convert it to?

Answer 5

1. Chemical work
2. Mechanical work
3. Transport work

Question 6

What is “chemical work”?

Answer 6

Utilizing energy for maintenance and growth
—-> Growing skeletal muscle hypertrophy
—–> Synthesizing cellular molecule
- Glucose to glycogen
- Glycerol and fatty acids to
triglycerides
- Amino acids to proteins

Question 7

What is Mechanical work?

Answer 7

1. Skeletal muscle for contraction
2. Smooth muscle for digestion, cardiac muscle for heart to beat

Question 8

What is Transport work?

Answer 8

Things from the extracellular/intracellular fluid like sodium and potassium is allow chemicals to move from lower to higher concentrations

Question 9

What is ATP (adenosine triphosphate)?

Answer 9

ATP + the energy currency of the body
- Energy from ATP hydrolysis
powers all forms of biological
work
- ATP is limited currency that
must continuously be
resynthesized at the rate of use
- the body stores 80-100
grams and 80 kilograms to
run a marathon