5. biochem summary

Question 1

why must catabolism and anabolism be balanced

Answer 1

catabolism provides the energy necessary for anabolism

Question 2

where does energy come from

Answer 2

the breakdown of glucose, fatty acids and amino acids from food into acetyl Co-A

Question 3

the utilization of Acetyl Co-A in the krebs cycle is which type of reaction

Answer 3

oxidation

Question 4

which species is really bad at using ketones as a source of energy for the brain

Answer 4

cows

Question 5

what substrate is required for use by red blood cellls

Answer 5

glucose (they dont have mitochondria

Question 6

what is glucose sparing and when is it used

Answer 6

occurs during starvation to maintain function of red blood cells if not enough glucose in body

Question 7

discuss glucose use in ruminants

Answer 7

• rarely produced as a result of enzymatic breakdown of food due to high cellulose content
• main source of glucose is from gluconeogenesis
• first dietary carbohydratees will be fermented into short chain VFAs in the rumen by microflora
• propionate is a VFA produced from cellulose fermentation and is the major substrate for gluconeogenesis
• propionate undergoes a series of esterification, carboxylation and catalytic steps to become isomerised into succinyl-CoA which can enter krebs

Question 8

what is basal energy requirement

Answer 8

• the amount of energy required on a daily basis for an inactive animal to keep its vital organs functioning
• of little practical interest as it describes the energy requirements of a fasting animal lying down but awake in a thermoneutral environment

Question 9

what is resting energy requirement

Answer 9

• the energy required by a relaxed animal
• amount of energy required per day for maintaining current bodyweight and avoiding catabolism of tissues while resting quietly in a stress free non fasted thermoneutral environment

Question 10

how is resting energy requirement calculated

Answer 10

for animals weighing between 2kg and 30kg: (30 x bodyweight in kg) + 70
for animals less tham 2 kg and over 30kg: 70 x (bodyweight in kg)^0.75

Question 11

what is maintenance energy requirement

Answer 11

• RER plus the energy needed for exercise, digestion and absorption of food
• species, repro status (lactating = LOTS of energy), age, activity level, other physiological requirements, disease, body condition

Question 12

this diagram represents which metabolic state

Answer 12

fed state

Question 13

this diagram represents which metabolic state

Answer 13

fasted state

Question 14

this diagram represents which metabolic state

Answer 14

starved state