Chapter 4: Carbohydrates
How many grams of carbohydrates do fruits and grains generally yield per serving?
15
How long does it take for the consumption of an adequate amount of carbohydrates to restore muscle glycogen levels to normal after exercise?
24 hours
Carbohydrates yield how many Calories per gram?
4
Up to how early can some ingested carbohydrates be used as an energy source following ingestion?
5-10 minutes
How many grams of carbohydrate per kilogram body weight are athletes in general training recommended to consume daily?
5-7
How long before prolonged exercise should carbohydrates be ingested to enhance performance? How many grams of carbs per kilogram body weight?
60-240 minutes; 4-5
What are the two common pathways in which protein, carbohydrates, and fat are all utilized for energy?
Krebs Cycle and Electron transport system
What is the order of the digestion tract?
Salivary gland/mouth, stomach, pancreas, small intestine, liver, large intestine, anus
during prolonged exercise, which specific muscle fibers are more likely to produce lactic acid and thus increase the perceived stress of the exercise
Type IIb
What causes muscle fatigue following high intensity exercise?
accumulation of hydrogen ions
What is the metabolic intermediate that is shared in common in the utilization of protein, carbohydrates, and fat for energy
acetyl-CoA
What are 2 examples of starches?
amylose and amylopectin
What are good sources of soluble fiber?
beans, dried peas, whole oats
How does dietary fiber exert health benefits?
binds substances like bile salts and increasing their exertion, stimulating peristalsis and speeding up intestinal transit, forming short chain fatty acids upon fermentation
Carbohydrates that are important for energy production during various forms of exercise are stored where?
blood as glucose, liver glycogen, muscle glycogen
What types of foods can increase the risk of developing dental caries?
chewy, sticky, sugary
fiber is considered a ____________
complex carbohydrate
What are the symptoms of hypoglycemia?
dizziness, muscular weakness, fatigue
What hormones increase blood glucose levels?
epinephrine, glucagon, and cortisol
What can carbohydrates be converted to and stored as in the body?
fat
What is insoluble fiber?
fibers that are not readily dissolved in water and not easily metabolized by intestinal bacteria
What are functions of carbohydrates besides providing energy?
formation of glycoproteins, glycolipids, and ribonucleic acid
Which monosaccharide is commonly found as a component in fruit?
fructose
which two monosaccharide for lactose?
galactose and glucose
What are the 3 parts of a whole grain?
germ, endosperm, bran
Nerve cells in the brain and retina and the red blood cells are normally dependent upon _________ for energy
glucose
What is the major monosaccharide found in the body?
glucose
What are the three simple sugars/monosaccharides?
glucose, fructose, galactose
What type of exercise is carbohydrates the primary energy fuel?
high intensity anaerobic events lasting less than 1 minute and high intensity aerobic events lasting more than an hour or two
glycogen stored in the __________ can later be reconverted to blood glucose
liver
What are the major storage sites for glycogen?
liver and muscles
In which sections of the gastrointestinal tracts does the digestion of carbohydrates by enzymes take place?
mouth and small intestine
Which organ secretes insulin?
pancreas
What is the primary function of carbohydrates?
provide energy
What enzyme is secreted in the mouth to begin the process of carbohydrate digestion in the human body?
salivary amylase
What are three characteristics of polysaccharides?
sometimes called complex carbohydrates, sometimes called starches, made of glucose units that are bonded together to form a chain
What is cane sugar or table sugar compose of?
sucrose
The carbohydrate source in sports drinks like Gatorade varies but usually contains a mixture of
sucrose, glucose, fructose
what are the three disaccharides?
sucrose, maltose, lactose
Why are carbohydrates an important energy source for exercise?
the metabolic pathways for carbohydrates are more efficient than those for fat, we can derive ATP more rapidly through glycolysis than from fat oxidation, and we derive more ATP from glucose than from a fatty acid
What is gluconeogenesis?
the new formation of glucose from either specific amino acids, glycerol or lactate
What happens to carbohydrates that are consumed after prolonged exercise as a replenishment meal?
used to re-synthesize muscle glycogen and can help restore blood glucose levels
When is glucose most likely used to produce fat?
when carbohydrate and overall calorie needs are exceeded
Where are complex carbohydrates primarily found?
whole grains, starchy vegetables, legumes