d1 quiz - biochemistry and digestion Flashcards
what are carbohydrates
1 carbon, 2 hydrogen and 1 oxyegn at least
main source of energy for the body
we can’t syntheize carbs so we obtain them from other sources
what are monosccharides
aka reducing sugars
signle sugar unit cointaining 3-8 carbons
switch between chain and cyclic forms
what are isomers
carbs with the same chem formula but arranged different ways
what are disaccharides
also type of reducing sugar
- contains 2 sugar units and more then 7 carbons
- formed by linking together of monosaccarides through dehydration syntheisis
- to break disaccharides into monosaccarides the opposite occors; hydrolysis which breaks apart the ether bond of the disaccharide
what is dehydration synthesis
involves the loss of hydroxide ion from one monomer and loss of hydrogen ion from another monomer to form a bond between the signle sugar units
(loss of water)
what are polysaccharides
complex carbohydrates with many simple sugars linked together
more diffucult for our bodies to break down
offer little energy as a result but good source of fibre
plants store in numerous ways
ex: startch and cellulose (makes up plant cell wall)
what are lipids and what are their functions
non polar molecules that repel water and have waxy or oily consistencey
fatty acid chains (hydrocarbon + carboxyl group) are lipid building blocks
- required to store energy provided by cells
- main component of cell membrane
- act as carriers for vitamins
-play role in synthesis of hormones
what are saturated fats
- bad fats
- consist of only signle bonds leading to rectangular shape which allows chains to pack together easily
soilds at room temp, hard to break down
what are unsaturated fats
- good fats
- at least one double bond in carbon chain leading to “kinked shape”
- means chains cannot be easily packed together
- tend to be liquid at room temp so are easy to break down
what is hydrogenation
converts unsaturated fats into saturated fats
breaking down of double bonds and addition of (H2)
what are triglycerides and diff between soild and liquid
formed by union of gylcerol ( 3-carbon lipid) and three fatty acids through dehyrdation syntheis
-soils: called fats and tend to be saturated and derived from animals
- lipids : called oils unsaturated and derived from plants
- act as stored energy for cells and relaseased into bloodstream in between meals
what are phospholipids
similar in structure to triglycerides but one fatty acid tail has been replaced by phosphate group
- contains both hydrophobic and hydrophillic ends meaning these lipids are polar
what is cholesterol (good and bad)
based on carbon ring structure, produced in liver
maintains cell membrane fludity and makes hormones such as testosterone and estrogen
- maintain cell membrane fludity and makes hormones such as testosterone and estrogen
- Bad (LDL) leads to plaque buildup in arteries
-Good(HDL) carries low density cholesterol back into liver
trans fats
chemically altered unsaturated fatty acids that increase LDL (bad cholesterol)
- formed through hydrogenation
what are ptoteins and functions
- made of amino acids
- controlls celluar functions and genetic opperations
- building reparing and maintence of all structure ex collagen and keration
- supplies energy but not main source
what is amino acid structure
central carbon bonded to hydrogen atom and amino acid group cointains nitrogen, carboxyl group and r group
r group determines what kind of protein it is
how do amino acids bond together
carbon ends bonds with nitrogen end
creating petide bond through dehyrdation synthesis
many bonded together refers as polypeptic chain
describe the protein structure
1) Primary structure: sequence of amino acids in protein
2) Secondary structure: way long strands of amino acid coil themslves Helix- telphone cord B-sheet folded like paper fan
3) Tertiary structure: once protein is coiled in will fold in on itself (3D) function of protein is dependent on this structure
4) Quaternary structure: complex of 2 or more poly peptide chains
what is denaturation
physical or chem factors distrupting bonds causing changes in shape
exposure to heat, radiation or changes in pH can alter protien shape
if the factors are removed protein can return to its original shape
what is Congulation
bonds holding protien together that are disrupted permanetly
what are nucleic acids
nitrgoen is in rings which is composed of funtional units called nucleotides
each is composed of 5-carbon sugar unit, phosphate molecule and nitrogen base
- can be double starned DNA or single started RNA
what are catalysts
substane controlling the spped of chemical reactions ( normally speeding them up)
what are enzymes
special protien catalysts premitting chem reactions to occor in the body at relativeky low temps which is done by reducing actvation energy of reaction
- provide alternative pathways for chem reactions and allow them to occor more efficently
- have -ase at the end of them
- found at fixed posotions on membrane of organelle such as mitochondria or ER
what are substrates
molecules enzymes work on
combine with enzymes at it activation sight
what are the two ways enzymes combine with substrates
1) Lock and key –> temporaily joining of the enzymes with the substrate
enzyme is lock which requires specifc enzyme molecule key
2) Induced fit —> Actual shape of active sight is altered slightly, when substrate molecules are trapped making the fit even tighter
what are cofactors
non protien inorganic molecules ex naturally occoring compounds such as oxygen, water carbon dioxide that are not produced by living things
* helps enzymes combine with substrate molecules *
what are coenzymes
organic molecules (large complex, cointaing carbon) often produced by liviing things
* helps enzymes combine with substrate molecules *
how does temp affect enzyme reaction
as increase in temp means increase in energy within a chem system therefore enzyme activity also increase
- beyond 37 dgrees celcius protiens start to denature (typically forming percipitate) so enzyme activity decreases
how does pH affect enzyme reaction
most function optimally at a specific pH when PH level changes the enzymes may began to denature
how does substrate concentartion affect enzyme reaction
enzymes can only cataluze reaction if the appropiate sustarte bonds to its active sight
substarte concentration increase, enzyme activity increases
how do competive inhibitors affect enzyme reaction
molecules with similar shapes as the shapes of substartes compete with subtrate for active sites
- as long as competitve inhibitors is bound to enzyme it is prevented from functionally normally
what are accesory organs
those which aid in digestion
- salivary gland, liver, gallblader, pancreas
what is the digestive tract
what moves food through the body
- mouth, esophagus, stomach, small and large intestine, rectum and anus
example movement of food within the digestive tract (simple)
-food enters through mouth
-passed down esophagus into stomach
- food enters small intestine
- prossed in small inetstine food is then processed into large intestine
- enters rectum where it is held until it is excreted
- what remains exists through anus
what is salivary amylase
- enzyme
- breaks down stratch into disaccarides
- produced by salivary galnds
- digests carbohydrates
- site of action: mouth
physical and chem digestion in mouth/ esophagus
teeth chew food into smaller pieces, as you chew your tongue pushes the bolus (ball of food) to back of mouth for swallowing
bolus enters the esophagus, moving towads stomach with wave like contractions
what is the esophageal spincter
bolus must pass through here
usally remains tightly shut to prevent stomach acid from splashing up into esophagus
physical/ chem digestion in stomach
physical- churning proccess as muscular layers contract
chem- stomach acid breaking down bolus
what is the chyme
cells lining the interior of the stomach secrete gaseous fluids
bolus + gastric juices
what are some things HCL does in stomach
- makes pH between 2-3, kills pathogens, denatures proteins
converts pepsinogen (inactive) to pepsin (active)
what is pepsin
protein digesting enzyme, starts breaking down protein present in food
- site of action: stomach, produced in linning of stomach
what protects stomach lining from being digested
alkaline ( basic mucus)
what is small inetstine
measure 7m in length and 2.5 cm in diameter
highly folded to increase SA by 600x
90% of digestion takes place here ( lipid, carbohydrate and protein digestion)
what are the 3 sections of the small inestine
- duodenum- 25 cm long, where most of digestion occors, accessory organ secrete juices into duodenum to aid in digestion
- jejunum - 3m long
- ileum- 4 m long
what are villi/ microvilli
folds ( villi) are converted to small cytoplamic projections called microvilli desgined for abosorption
increase SA by abosbition
more electrolytes by diffusion and move water by osmosis
what are lacteal
vessel projection of lympathic system, desgined to absorb fats
what are cappillaris
vessels of circulatory system for aborbiton of all other nutrients for immediate transport to liver for proccessing
what is enteric gastrin
acts on stomach cells
stimulated by partially digested protiens
stimulates gastric juice secretion and promotes stomach empyting although low pH inhibites this
what is cholecystokinin
stimulated by partially digested protiens and irritants in the chyme
stimulates pancreatic enzyme relase and bile from gall blader
what is secretin
in response to acids in duodenum
inhibts secretion of gastric juice
stimulates sodium bicarbonate relase by pancrease
simulates bile scretion by liver
what is the pancreas
lies behind stomach
has both secretory and hormonal functions
realses digestive enzymes
releases sodium biocarbonate in duodenum to neutralize stomach acif
what are pancreas digestive enzymes
delivers fluid to small intestine
what is trypsin and chymotrypsin
digest proteins in amino acids
site of action: small inestine
site of production: pancreas
what is pancreatic amylase
digest startch into disaccharides
site of action: small inetsine
site of production pancreas
what is lipase
digest lipid into fatty acids
site of action: small intestine
produced by pancreas
4 functions of the liver
1) production of bile - helps lipases break down fats
2) storage of glucose - in form of glycogen
3) detoxification of blood- makes enzymes break down toxins
4) deamination of amino acids
what is hepatiis
infection resulting in formation of scar tissue on liver
what is gall bladder
bile is stored here ( bile salts , water, cholesterolr and bile pigments)
storage between meal and injects bile as needed into small inetstine
what is the main function of the small inetstine
complete digestion of macromolecules and to absorb resulting nutrients
once nutreients are digested and brown down into monomers they can be abosrbed into bloodstream
functions of large intestine/ colon
aborbtion of water and electrolytes
- production fo feces ( consits of water, inorganic salts, cells from GI tract, bacteria and undigested food)
- stores water though pumping Na ions into capillars drawing water out of lumen by osmosis
houses bacteria to make viatmin b and k
what do cells in lining of large intestine produce
mucus for lubricatioan and bicarbonate for acidc fermentation process
what is fermentation
performed by bacteria that are ingested when eating
movement through large inetstine is slow and allows for growth of nacteria
these bacteria are reffered to as colonizers
what is lactase
enzyme
site of action: small inestine and produced in lining of SI
digests carbohydrates
what is maltase
enzyme
site of action: small inestine and produced in lining of SI
digests carbohydrates
what is sucrase
enzyme
site of action: small inestine and produced in lining of SI
digests carbohydrates
what is peptidase
small inestine
lining of small intestine
digests protiens
what is hemoglobin
protien in red bloood cells carrying oxygen
4 steps to carbohydrate digestion
1) starch digestion begins with enzyme salivary amylase but it is minmal here (stomach) due to acidic conditions
2) Most starch digestion happens in small intestine where enzyme pancreatic amylase breaks startch into simpler sugars discardies
3) Other enzymes hydrolize ( break down) these into monosacchardies such as glucose which are abosorbed into bloodstream and transported to liver
4) This requires atp produced in mitochodria
what are the steps to protein digestion
proteins first broken down in stomach by enzyme pepsin
2) In small intesine enzymes from pancreas ( trypsin and chemotrypsin) further break down protiens into shorter chains called peptides
3) Other enzymes split peptides into individual amino acids which are absorbed into bloddstream through small intestine
4) amino acids travel to liver where they are used for energy, converted to sugar or used to build new proteins
what are the steps in lipid digestion
1) Fats arrive in duodenum where bile is released emulifying fats
2) lipids can then help break down fats through hydroloysis
3) Resulting fatty acids are absorbed into cells of villi by diffusion
4) Coated with protein to make them soluble where lymph vessels carry to chest region where they join bloodstream
