week 3: macro nutrients support of E availability

Question 1

define macronurtient

Answer 1

• deitary need of the body in relitvely large amounts daily
• is energy yeilding
• eg. carbohydrates, fats, protiens

Question 2

define micronutrient

Answer 2

• dietary requirement need in small amounts
• “special building items”
• vitamins, minerals, antioxidants

Question 3

how do macronutrients provide energy

Answer 3

• the ability to perform physical activity depends on capacity of energy we are able to extract from food, using catabolic pathways
• carbs, fats and protiens use different pathways
• each fuel type turns over H2o, Co2 and ATP
• ATP is the only product able to produce muscle contraction

Question 4

what is carbohydrates purpose

Answer 4

• split into monmosacharides and converted to glucose for production of energy
• glucose is used to fomr part of DNA and RNA
• combines with protiens to form glycoprotiens

Question 5

where are carbohydrates stored

Answer 5

• in liver and skeletal muscle as glycogen

Question 6

what is the purpose of fats/lipids

Answer 6

• triglygerides used for energy production my skeletal muscle
• when stored it insulates and protects organs
• forms plasma membranes of cells, bile, and myelin sheath of axons
• cholesterol used in plasma membrane, bile and steroid hormones

Question 7

where is fat stored

Answer 7

• adipose tissue
• liver

Question 8

purpose of protiens

Answer 8

• broken into amino acids and used for energy production
• form collagen and structural strenth
• form actin and myosin in muscle
• form enzymes
• act as buffers in the blood
• promote clotting
• transport o2 and Co2

Question 9

where are protiens stored

Answer 9

as a lipid in adipose tissue in liver
- excess amino acids are secreted

Question 10

how is carbohydrate energy accessed

Answer 10

in anerobic and aerobic energetics

anerobic (instantaneous, ATP-PC, glycolosis combined)
- C6H12O6 (glucose) + 2ADP + 2Pi +2NAD+ → 2 pyruvate +** 𝞔 (2ATP)** +2NADH +2H+

aerobic (krebs, ETC):
- C6H12O6 + 6O2 (glucose) → 6CO2 + 6H2 O +** 𝞔 (30-32ATP)**

Question 11

how is lipid/fat energy accessed

Answer 11

• overall energy is through oxidative metabolism
• lipids are an aerobic energy source
• during submaximal excercise, carbs and fat are equal suplliers

glycogen sparers:
- when excercising at lower intensites fats are main source so that glycogen stores can be spared

intramuscular TGLS: (triglyscerides)
- used as a fuel, determined by intensity of excerice, duration, age etc.

Question 12

how are intramuscular TGL’s used as energy

Answer 12

lipolosis:
- process when hormone sensitive lipase (HSL) break triglcerides (TGL’s) in adipose tissue, into plasma free fatty acids (FFAs) and glycerol

• Fatty Acids obtained from lipolysis are oxidized to Acetyl-CoA
• Acetyl-CoA is then used in the CAC in the Mitochondria
• Due to structure: TGL’s yield >2x the 𝞔 per unit mass than CHO & Protein!
• we have a short supply of FFA’s that are used when body is at rest, therfore stores need to be replenished by TGLs

Question 13

how do we access energy through protiens

Answer 13

• if required smino acids can be used for energy but only make small amount
• when AAs are processed, other molecules are produced, such as pyruvate
• these can become energy by entering the CAC
• excess AA’s can also be converted to glucose or ketones
• glucose can be used for energy directly (glycolosis) or storage
• ketones can be oxidised for acetyl COa which can be used in CAC