Chapter 4: Carbohydrates Flashcards
what are unrefined foods? give an example.
food eaten just the way they are
example) whole grains, vegetables, fruit
what are refined foods? give an example.
foods that have undergone processing to remove coarse parts of original food
example) candy, cookies
what is a whole grain? give an example.
whole grains contain the entire kernel of the grain (germ, bran, and endosperm)
example) oatmeal, whole wheat toast
what is germ?
- base of the kernel
- embryo where sprouting occurs
- source of oil and vitamin E
what is bran?
- the outer layer of the kernel
- contains the most fibre
- source of minerals and vitamins
what is endosperm?
- largest part of kernel
- made of starch, protein, vitamins, and minerals
what is enrichment?
addition of some nutrients to refined grains
what is fortification?
addition of nutrients to foods
what do refined sugars lack?
lacks healthy micronutrients, phytochemicals, fibre, vitamins, and minerals
what are empty calories?
energy with few nutrients
what are sugar units?
smallest unit of carbohydrate molecule
what are monosaccharides?
- a carbohydrate made of a single sugar unit
- contains 6 carbon, 12 hydrogen, 6 oxygen
what are dissacharides?
a carbohydrate made of 2 sugar units
what are polysaccharides?
a carbohydrate made up of more than 2 sugar units
what are simple carbohydrates?
monosaccharides and disaccharides
give 3 examples of monosaccharides.
- glucose
- fructose
- galactose
give 3 example of disaccharides.
- maltose
- sucrose
- lactose
what is glucose?
- 6 carbon monosaccharide
- primary form of carbohydrates used to provide energy
- brain and red blood cells rely solely on glucose for fuel
what is glycogen?
- storage for of glucose in humans
- found in liver and muscles
what is starch?
- carbohydrates in plants (endosperm) made of many glucose molecules
- for plant growth and reproduction
what is fibre?
a complex carbohydrate that cannot be broken down by human digestive enzymes
what is soluble fibre? give an example.
- fibre that dissolves in water or absorbs water
- can be broken down by intestinal microbiota
- lowers cholesterol
- regulates blood sugar
example) apples, oats, beans, seaweed
how many kcals does fibre provide per 1 gram
2 kcals
how does intestinal microbiota break down soluble fibre?
ferments soluble fibre to produce short-chain fatty acids for energy
how does soluble fibre lower cholesterol?
binds to cholesterol and promotes it’s excretion
how does soluble fibre regulate blood sugar?
delays gastric emptying, reducing the risk of type-2 diabetes
what is insoluble fibre? give an example.
- comes from the structural part of plants (cell wall)
- doesn’t dissolve in water or broken down by microbiota
- promotes intestinal health and regular bowel movements
example) wheat and rye bran, broccoli, celery
how does insoluble fibre promote intestinal health?
speeds passage through intestines while binding to toxic waste
how do we digest carbohydrates?
step 1: salivary amylase breaks down starch
step 2: digestive enzymes in small intestines break down disaccharides and complex carbohydrates into monosaccharides
step 3: pancreatic amylase in small intestines digest amylose, maltase digests maltose, sucrase digests sucrose, and lactase digests lactose
how is bloating and gas produced?
when carbs are passing through the colon unchanged
what happens to lactose levels as you get older?
lactose levels decrease causing lactose unable to be fully digested
what is lactose intolerance?
inability to digest lactose due to inadequate lactase
what are 2 indigestible carbohydrates?
- oligosaccharides
2. resistant starch
what are oligosaccharides?
short carbohydrate chains with 3-10 sugars
what are resistant starches? give an example.
can’t be digested due to natural structure or cooking altering digestibility
example) legumes, cold potatoes, rice, pasta
what are the functions of indigestible carbohydrates?
- slows the rate of nutrient absorption and prevents it
- speeds up transit time
what is a glycemic response?
rate, magnitude, and duration of rise in blood glucose that occurs after food is consumes
what is the relation between refined sugars and glycemic response?
refined sugars cause a greater glycemic response bc they leave the stomach faster and it rapidly digested/absorbed
what is the relation between fibre and glycemic response?
fibre takes longer to digest, therefore, has a smaller glycemic response
what is insulin?
a hormone in the pancreas that brings glucose to body cells to drop glucose levels
what is glucagon?
hormone that raises blood glucose levels by stimulating liver cells to breakdown glycogen > glucose, bringing glucose levels up
what is glycolysis?
- first step of cellular respiration
- anaerobic metabolic pathway that splits glucose into 2 three-carbon pyruvate molecules
- produces 2 ATP molecules from 1 glucose
what is anaerobic metabolism?
- metabolism without oxygen
- produces lactic acid, called “the burn”
what is aerobic metabolism?
- metabolism with oxygen
- breaks down glucose > CO2, water, and ATP
- produces 30+ ATP molecules from 1 glucose
what are ketones?
molecules formed when there are no carbohydrates to make acetyl CoA for energy
what is ketosis?
- high levels of ketones in the blood
- increases acidity and disrupts normal body processes
- occurs during starvation or low-carb diets
- can cause a coma or death
what are symptoms of ketosis?
- reduced appetite
- headache
- dry mouth
- bad breath
what is diabetes mellitus?
disease characterized by high blood glucose levels caused by insufficient or decreased insulin
what is type-1 diabetes?
- autoimmune destruction of insulin-producing cells
- requires injection of insulin to maintain blood glucose levels
what is an autoimmune disease?
disease that results from immune reactions destroying normal body cells
what is type-2 diabetes?
- characterized by insulin resistance and deficiency
- body doesn’t produce enough insulin or is insensitive to it
- blood glucose levels remain high and toxic to vital organs
what are prediabetes?
condition in which glucose levels are high but not high enough to be diagnosed as diabetes
what is gestational diabetes?
- elevation of blood sugar during pregnancy
- can put fetus at risk for more complications
- normally goes after pregnancy or stays as type-2
what are symptoms of diabetes?
- frequent urination
- thirst
- blurred vision
- weight loss
what is hypoglycemia?
abnormally low blood glucose levels
what are symptoms of hypoglycemia?
- sweating
- shaking
- anxiety
- seizures
what is fasting hypoglycemia?
occurs when an individual hasn’t eaten
what is reactive hypoglycemia?
occurs in response to consumption of high-carb foods
what are caries?
occurs when teeth bacteria metabolize carbohydrates, producing teeth acid
how can diets how in unrefined carbohydrates be problematic in children?
they may get full before meeting their nutritional needs
what are artificial sweeteners?
a replacement for refined structure with 0 calories
what is diverticulosis?
condition where sacs form in the intestinal wall
what is the RDA for carbohydrates/day
130g/day
what is the AMDR for carbohydrates?
45-65%
what is the adequate intake amount for carbohydrates?
38g for men
25g for women
