APK4163 midterm

The wave of muscular contraction that drives food through the digestive system is called

Peristalsis

The enzyme amylase is involved in the digestion of which macronutrient?

Carbohydrate

Amylase is inactivated by the acidic environment of the stomach. Therefore, carbohydrates are not digested in the stomach.

True

The acidic environment of the stomach activates which of the following enzymes?

Lingual Lipase and Pepsin

The first 10 inches of the small intestine is called the

Duodenum

In the duodenum of the small intestine

stomach acid is neutralized, pepsin is activated, pancreatic enzymes take over digestion

Most intestinal digestion occurs in the

Duodenum

Pancreatic enzymes are secreted into which part of the small intestine

Duodenum

Digestion and absorption are enhanced due to increase surface area of the small intestine. Which of the following structures serve to increase intestinal surface area? Select all that are true

Circular folds, villi, microvilli

The final stage of enzymatic digestion in the small intestine is carried out by

Brush border enzymes

Dietary carbohydrate is digested primarily by

 

the pancreatic enzyme α-amylase and to a lesser extent by salivary α-amylase

Glycolysis is the sequence of reactions that metabolizes one molecule of glucose to two molecules of pyruvate

True

The primary control of muscle glycolysis is the the ratio of ATP to ADP. This is known as the energy charge of the cell.

False

What is the rate limiting step of glycolysis (The most important control site of the glycolytic pathway)?

Phosphofructokinase

Which of the following are true? (more than one answer may apply)

Glucagon stimulates the mobilization of amino acids and fats 

Glucagon stimulates gluconeogenesis

Insulin stimulates the muscle and liver to store glucose as glycogen

Glucagon is secreted by the liver

Glucagon stimulates the mobilization of amino acids and fats

Glucagon stimulates gluconeogenesis

Insulin stimulates the muscle and liver to store glucose as glycogen

Catabolism and Anabolism occur under different regulatory pathways, therefore they can happen simultaneously

True

You may expect carbohydrates to be utilized more heavily in which of the following activities.

200-meter hurdles

Which of the following is most true?

During oxidative phosphorylation (electron transport chain), ATP is generated through.....

Pumping protons from the intermembrane space to the matrix

Very little ATP is produced in the Krebs cycle. The main purpose of the Krebs cycle is to generate electrons for use in oxidative phosphorylation.

True

Lactate can be converted back to glucose via gluconeogenesis in the liver

True

Which form of Starch will digest more efficiently?

Amylopectin

Amylopectin is more highly branched than glycogen

False

Approximately how many kilocalories of energy can the average individual (70 Kg) store in the form of muscle glycogen? 

2000

The glycemic index/load (ability of a food to raise blood glucose levels) will be higher for a more highly branched starch

True

A high glycemic index food will result in a longer period of satiety

False

Which of the following is true with regards to the following image? Hint: More than one may apply!

 Glycogen replenishment was inadequate following day 1 and day 2

The athlete will NOT be able to maintain performance on day 3

A 20-50% reduction in muscle glycogen content has been reported following an acute resistance exercise – even when LOW total work loads are encountered.

True

When exercising at 20-30% of VO2max, there is a substantial utilization of muscle glycogen.

False

Regular exercise has been shown to increase the sensitivity of both the liver and skeletal muscle to insulin. This means that

 

Less Insulin is needed to regulate blood glucose

High glycemic foods should be consumed

During prolonged aerobic endurance exercise and immediately after a workout

During digestion, triglycerides are broken down into a monoglyceride and 2 free fatty acids. These individual units are then transported to the enterocyte via micelles where they are re-synthesized into triglycerides within the smooth endoplasmic reticulum. The resultant triglycerides are then packaged into chylomicrons by the golgi complex and released into the lymph system by exocytosis.

True

Triglycerides are stored in adipocytes and undergo a constant turnover of molecules every 3 weeks. This means that they are released into the blood where they are either oxidized via beta-oxidation, or re-deposited in other fat cells.

True

When triglycerides are hydrolyzed (broken down), the resultant glycerol molecule can be converted to glucose in the liver. It is converted to __________, which is converted to ___________ for entry into the citric acid (Krebs) cycle.

glyceraldehyde-3-phosphate

acetyl-CoA

Fatty acids are distinguished as either good (unsaturated) or bad (saturated) based upon their (check all that apply)

saturation

structure

chain length

The triglycerides in adipose tissue are broken down into glycerol and free fatty acids by the enzyme

 

hormone-sensitive lipase

Diets too low in fat are associated with reduced testosterone and exercise performance

True

The short form of "hormone sensitive lipase" is expressed in the testicles

False

The process used in the food industry in which hydrogen gas is bubbled through oil at a high temperature to create trans fatty acids is called

hydrogenation

A lower ratio of omega-6 to omega-3 fatty acids is more desirable in reducing the risk of many of the chronic diseases of high prevalence in Western societies

True

Inadequate fat intake may have which of the following effects? (check all that apply)

 

Reduce energy at rest and during low-intensity exercise

Reduce "good" cholesterol

Result in malabsorption of fat-soluble vitamins

This protein structure occurs when certain attractions are present between alpha helices and pleated-sheets

 

Tertiary Structure

Amino acids can be converted to intermediates of the citric acid (Kreb's) cycle. When is this likely to occur (check all that apply)

During a low-calorie diet

During a low-carbohydrate diet

During prolonged endurance exercise

The RDA (recommended daily allowance) of protein has historically been overestimated. In accordance with the re-evaluation of protein RDA's, what is the protein RDA for a sedentary individual?

 

1.2 g/kg/bw

The intracellular sensor for protein synthesis (muscle growth) is

 

mammalian target of rapamycin (mTOR)

Leucine is the key amino acid involved in the stimulation of protein synthesis

True

Which of the following is a functional role of Protein?

energy

hormones

enzymes

antibodies

Which organ serves as the critical center in amino acid metabolism?

liver

Nitrogen balance is an indicator of protein intake

True

Which of the following scenarios will likely result in amino acids being used as a fuel substrate? (check all that apply)

Very-low calorie diets

Prolonged endurance exercise

 Overtraining

Essential amino acids of the appropriate dosage will stimulate protein synthesis for how long?

2-3 hours