digestion 2 Flashcards
process of breaking things into molecules
chemical digestion
every bond broken of a polymer requires one molecule of water; rxn breaking things DOWN
hydrolysis
forms of carbohydrates (3):
- monosaccharides
- disaccharides
- polysaccharides (oligosaccharides)
monosaccharides (3):
- glucose
- fructose
- galactose
disaccharides (3):
- sucrose
- lactose
- maltose
polysaccharides (3):
- glycogen
- starch
- cellulose
can you absorb disaccharides?
no
which polysaccharide starts digesting in the mouth?
starch
what form of carbohydrates can absorb?
monosaccharides
what do we use monosaccharides for after we absorb them (2)?
- energy
- building blocks
specific type of polysaccharide
oligosaccharides
location and substrate of: salivary amylase
mouth (salivary gland)
starch
location and substrate of: pancreatic amylase
small intestine (pancreas) starch
location and substrate of: dextrine
small intestine (brush border) oligosaccharides
location and substrate of: glucoamylase
small intestine (brush border) oligosaccharides
location and substrate of: maltase
small intestine (brush border) maltose
location and substrate of: sucrase
small intestine (brush border) sucrose
location and substrate of: lactase
small intestine (brush border) lactose
where does protein digestion start?
stomach
protein digestion is _____ and _____
dieatary and intrinsic
intrinsic components of protein digestion (2):
- enzymes
- mucosal cells
intrinsic component of protein digestion: forms of protein themselves; breaks down polypeptide chains into amino acids; produced in INACTIVE FORM FIRST
enzymes
enzymes that digest PROTEIN (7):
**products become substrate of next enzyme
1) pepsin
2) rennin
3) trypsin
4) chymotrypsin
5) carboxypeptidase
6) aminopeptidase
7) dipeptidase
where is pepsin produced?
chief cells (in stomach)
where is rennin produced?
in babies
where is trypsin produced?
pancreas
where is chymotrypsin produced?
pancreas
where is carboxypeptidase produced?
pancreas/brush border of small intestine
where is amino peptidase produced?
brush border of small intestine
where is dipeptidase produced?
brush border of small intestine
2 protein enzymes that take single amino acids off the end of the polypeptide chain
carboxypeptidase + aminopeptidase
enzyme that babies produced that help them break down proteins (casein and whey) in milk; slowly diminishes with age
rennin
what does lipase break down?
lipids
where does the digestion of lipids both START and STOP?
small intestine
where is lipase produced in its ACTIVE FORM?
pancreas
why is lipase produced in its active form by the pancreas?
increases its efficiency with the presence of bile (emulsifies fat)
lipase breaks down lipids into _____ _____ and _____, which are absorbed in the small intestine
fatty acids + glycerol
long chains of nucleotides so that we can make our own; replicated in mitosis
DNA and RNA
nucleic acid enzymes (3):
**products become substrate of next enzyme
- pancreatic nuclease
- nucelosidase
- phosphatase
where is pancreatic nuclease produced?
pancreas
where is nucleosidase produced?
brush border of small intestine
where is phosphatase produced?
brush border of small intestine
types of absorption processes (2):
- active transport
- simple diffusion (passive transport)
active transport absorption process:
active transport into villi capillaries and delivered to liver via endocytosis (usually use a vesicle)
simple diffusion absorption process:
simple diffusion into villi lacteals and delivered to blood by lymph
if molecules are fat soluble in the simple diffusion absorption process, it goes into ______ and THEN ______
lymph —> lacteals
simple diffusion absorption process is aided by _______
micelles (surround lipids)
all aborption occurs prior to the ______
ilium (aka it occurs in duodenum and jejunum; ileum just absorbs bile salts)
nutrients are substances used by the body for (3):
- energy
- growth
- repari
____% of the food we eat is water
60%
types of nutrients (6):
- water
- carbohydrates
- lipids
- proteins
- vitamins
- minerals
type of nutrient: major nutrient; mostly from plants
carbohydrates (glucose)
type of nutrient: major nutrient; mainly from triglycerides; from plants (unsaturated) or animals (saturated)
lipids
effect of unsaturated fats from plants on body =
neutral effect OR decrease cholesterol
effect of saturated fats from animals on body =
increase cholesterol
types of nutrient: from plants or animals; can only get ALL essential monomers from animals
proteins
we can only get ALL essential amino acids from ______
animals
animal = _____ protein
complete
plan = ______ protein
incomplete
types of nutrient: co-enzymes for enzymes in our body; needed to metabolize/get nutritional value from everything else
vitamins
what happens if we have excess WATER-SOLUBLE vitamins?
eliminate in our pee
what happens if we have excess FAT-SOLUBLE vitamins?
accumulate in bile = toxic!
type of nutrient: available in food; calcium + phosphorus are the MOST important (make up salt that builds up bone)
minerals
2 most important minerals that make up the salt that builds up bone
calcium + phosphorus
the _____ has the ability to convert one macronutrient to another
liver
biochemical process of conversion of macromolecules (big little)
metabolism
two types of metabolism:
- anabolism
- catabolism
type of metabolism: small —-> BIG; build up
anabolism
type of metabolism: BIG —-> small; break down
catabolism (my cat breaks down everything)
overview process of metabolism (3):
1) chemical digestion (CATABOLIC) and transport of products to cells
2) anabolism of lipids, proteins, and glycogen OR catabolism of pyruvic acid and acetyl-CoA
3) cellular respiration in mitochondria (prod. ATP; conversion of energy)
redox enzymes (3):
- dehydrogenases
- oxidases
- coenzymes
type of redox enzyme: catalyzes oxidation
dehydrogenases
type of redox enzyme: catalyze transfer of oxygen
oxidases
type of redox enzyme: hydrogen (H+) ACCEPTORS; NAD and FADH
coenzymes
REMOVAL of hydrogen (H+) or oxygen is added; lose energy
oxidation
ADDITION of hydrogen (H+) to something; add energy
reduction
during oxidation, you _____ energy
lose
during reduction, you ____ energy
add
oxidation and reduction rxns are _____ together
paired
if we do not use subunits of food immediately for energy or for building blocks, what happens to it?
put into storage
type of ATP synthesis: direct transfer of phosphate form something else; ADP –> ATP; “direct phosphorylation”
substrate-level phosphorylation
types of ATP synthesis (2):
- substrate-level phosphorylation
- oxidative phosphorylation
human body is designed around use of _____ for energy
glucose
type of ATP synthesis: reduced co-enzymes go through the electron transport chain to form a chemiosmatic gradient; gradient made out of ions (H+); a LOT more energy is produced
oxidative phosphorylation
carbohydrate metabolism (4):
1) glucose enters cells by facilitated diffusion (out of blood into cells; “glucose uptake”)
2) gluocse immediately phosphorylated to glucose-6-phoshpate (***maintains graident of the influx of glucose)
3) glycolysis continues and results in formation of 2 molecule of pyruvic acid, 2 molecules of NADH and a net gain of 2 molecules of ATP
4) if oxygen is present, oxidative phosphorylation occurs (each pyruvate can enter into this)
– then enters krebbs cycle + ETC
if no oxygen is present during carb. metabolism, pyruvate is turned into _____ _____
lactic acid
accumulation of lactic acid can change ____ and _____ _____ (shuts off processes)
pH
denature enzymes
carbohydrate metabolism is actually ____ steps and requires
10 steps
enzymes
for oxidative phosphorylation to occur, what has to be present?
oxygen
oxidative phosphorylation process (
1) pyruvic acid converted to acetyl-CoA in mitochondria – generates CO2 + NADH
2) acetyl-CoA enters Krebs Cycle – generates 2 CO2, 2 NADH, 1 ATP, and 1 FADH
3) reduced Kreb’s cycle coenzymes eneter ETC
4) hydrogens used to phosphorylate ADP – generates water + 34 ATP
excess glucose process (3):
1) high ATP levels stop glycolysis (no more ATP)
2) glucose converted to glycogen = glycogenesis
3) glycogen stored until energy needed
production of glycogen from glucose; reversible rxn
glycogenesis
where is glycogen stored (2):
- skeletal muscle
- liver (polymineralization)
drop in blood glucose stimulates ________
glycogenolysis
insufficient glucose availability prompts conversion of glycerol + amino acids to glucose; occurs in LIVER
gluconeogensis
lipid metabolism (
1) absorbed lipids broken down by plasma enzymes into glycerol + fatty acids
2) glycerol converted to glyceraldehyde phosphate
- glyceraldehyde phosphate converted to pyruvic acid in glycolysis
- then enters Kreb’s cyce (if oxygen is present)
3) fatty acids broken down into acetic acid in mitochondria
- acetic acid fused with CoA to form acetyl-CoA
- also enters Kreb’s
fat produces ___ times more ATP compared to glucose
10x
excess lipids process (2):
1) high ATP and glucose levels tirgger conversion of glycerol and fatty acids into triglycerieds for storage
2) lipolysis reverses process
protein metabolism (2)
1) amino acids deaminated (take amine group off — remove ammonia)
2) deaminated molecules converted to pyruvic acid or into Kreb’s intermediates
order of macromolecules used for energy:
- carbs
- lipids
- proteins (last resort)
excess protein process (2):
1) high ATP levels cause pyruvic acid formed through deamination to be converted to glucose (goes thru glycogenesis to form glycogen)
2) hormones control protein synthesis ON ribosomes
