Biochem exam 1

vivo

real life

vitro

studies in control setting or lab

4 types of biomolecules

proteins, nucleic acids, lipids, carbs

ester

acid + alcohol

ethers

alcohol + alcohol

amides

acid + amine

thioesters

thiol + ester

what makes a compound organic

hydrocarbon

why is isomerization important

determines how a molecule will fit or interact with other molecule

what is the difference structural isomers and steroisomers

structural- same make up different order

stereoisomers- same make up different 3D configuration

how are enantiomers and diastereomers different

enantiomers- mirror images

diastereomers- not mirror images

why are geometric isomers important to health

• cis and trans fatty acids

• trans increase all cause mortality

• cis are healthy and lower heart disease and cvd mortally

oxidation-reduction (LEO)

• oxidation: loss of electron (increase charge)

• reduction: gain of electron (reduce charge)

dehydration

water is a product

hydrolysis

• water is a reactant

• break a single bond

hydration

• water is a reactant

• water breaks a double bond

methylation

gain methyl group

phosphorylation

gain phosphate group

does a reaction or pathway proceed on its own when gibbs free energy is positive or negative

gibbs free energy needs to be negative to happen on its own

what does it mean when enthalpy is negative

• entropy- randomness of reactions happening

• when negative less random

• positive more random

what does positive entropy mean

more random

what is the difference between exergonic and endergonic

• exergonic - releases energy

• endergonic - requires energy

what is energy coupling

combining gibbs and exergonic/endergonic

what determines if a substance can dissolve in water

• polar or non polar

• polar biomolecules dissolve easily

what is required for hydrogen bonds to occur

hydrogen donor and acceptor

electrostatic

between two charged particles or ions

attractive and repulsive

london dispersion forces and van der waals

weakest, interaction any two atoms in close proximity, between 2 uncharged compounds

hyrophobic

non-polar - non-polar

what are examples of passive transport across membranes

passive - no energy

• osmosis

• facilitated diffusion

• passive or simple

which types of compounds are more likley to permeate through a cellular membrane

small non polar and uncharged

how is H+ related to pH

higher H+ = lower pH

lower H+ = high pH

why is pH important in the body

affects structures and activity of macronutrients

• small changes in pH can cause lage change in protein structure and function

are weak acids proton donors or acceptors

weak acids are donors, bases are acceptors

what is the difference between monoprotic, diprotic and tripotic acids

amount of H+ ions they lose

• mono = 1

• di = 2

• tri = 3

what does it mean when the pH is below the pKa? What about when the pH is above pKa? What are the biochemical acids and biochemical bases

pH below pKa - going to hold onto their H+ ions

pH above - going to lose their H+ ions

what is the difference between acidosis and alkalosis

acidosis- high pH

alkalosis - low pH

what are the main intracellular and extracellular buffers

• intracellular- protein buffer system (proteins can act like a base or a acid)

• extracellular - bicarbonate-carbonic acid buffer system (respiratory and renal system)

how is pH regulated in body

buffers

what is the difference between respiratory and metabolic buffers

respiratory - dictate breathing rate to control pH

metabolic - excrete or use renal to control pH

what is respiratory acidosis/alkalosis

acidosis - CO2 concentration high, breathing rate speeds up

alkalosis - CO2 concentration low, breathing rate slows

what is metabolic acidosis/alkalosis

• acidosis - loss of bicarbonate or excessive nonvolatile acids

• alkalosis - excessive bicarbonate production

which types of study designs are better than opinions and case studies

meta analysis, systematic reviews, randomized control trail

what is the difference between absolute risk, relative risk, odds ratio

AR- true incidence (absolute difference)

RR- probability of risk

OR- odds ratio

what is NNT

number of people that need to be treated for one to have the effect or benefit

want NNT below 10

what is the difference between correlation and causation

• correlation means there is an associate

• causation means a direct effect is there (only determined through RCT)

what are the functions of the GI tract

mobility, secretion, digestion, absorption, excretion

what are the 4 layers of the GI tract

muscularis, submucosal, mucosal, lumen

function of muscularis

move and mixes food

what are the 4 types of communication in the gut

endocrine

• gastrin

• CCK

• ghrelin

• secretion

• motilin

nuerocrine

• ach

• norepinephrine

paracrine

• histamine

• somatostatin

immune

what neurotransmitters are released from the parasympathetic and sympathetic neurons and what impact do they have on the GI tract

• acetylcholine stimulates

• norepinephrine inhibits

does sympathetic activation have a stimulatory or inhibitory effect

inhibitory

where is the enteric system located and what is it function

• submucosal (submucosal plexus) and muscularis externis (myenteric plexus)

• submucosal plexus - controls secretions

• myenteric plexus - controls peristalsis

what controls movement in the SI

myenteric plexus

what is the law of the gut

distention

know how peristalsis is controlled (frequency and strength of the contractions)

frequency - interstitial cells of cajal

strength - autonomic nervous system, hormones and neurotransmitters

what are segmental contractions and what are they important for

squeezing from the circular muscles on the chyme

• important for exposure to absorptive surface and mixing of chyme

what is the difference between phasic and tonic contractions and where is each located

phasic - period contraction, followed by relaxation

• esophagus, gastric antrum, SI and LI

tonic - constant contraction unless told not to (sphincters)

list the parts of the digestive tract

mouth, salivary glands, pharynx, esophagus, stomach, small intestine, liver, pancreas, gallbladder, Li, anus

what happens during the cephalic phase, gastric phase and intestinal phase of digestion

• cephalic - carbs and lipids

• stomach - lipids and proteins

  • gastrin stimulates most of stomach

  • cheif cells

  • parietal cells

  • g cells

  • mucous cells

• SI - carbs, lipids, proteins

  • bile made from cholesterol in the liver that is stored in the gallbladder and released into the duedenum for digestion of lipids. duodenum also has a brush boarder enzyme that absorb carbs and proteins

  • jejunum recieves and absorbs through enterocytes that have a brush boarder enzymes that absorb carbs and proteins

  • ileum has absorption of specialized molecules such as B12 that is absorbed by intrinsic

  • factor - also has endocytosis (pinocytosis, phagocytosis, receptor mediated endocytosis (B12))

• LI - no digestion or absorption only fermentation

  • fermentation is taking left over nutreints and converting them to gas for nutrients and creating short chain fatty acids

what is the function of saliva

• digests carbs and lipid

• dilute and buffer ingested foods

• lubrication

know the stages of swallowing

• oral - chewing

• pharyngeal - opening sphincters and closing air way

• esophageal - peristalisis

list the parts of the stomach

• fundus

• body

• antrum

lost cells of the stomach and what they secrete

• parietal - HCl (body)

• chief - enzymes (body)

• g cells - gastrin (antrum, caudad)

• mucosus - mucus, little bit of bicarbonate (antrum, caudad)

list factors that can affect gastric emptying, secretions, and motility

• solid or beverage (beverage digest faster)

• presence of fat and amino acids that stimulate release of CCK

  • CCK inhibits gastric emptying

• presence of H

where does retropulsion occur

gastric juice + bolus = chyme

• hcl

• enzymes

• intrinsic factor

• mucus

which hormones stimulate hunger? which stimulate satiety?

controlled by hypothalamus

• hunger - ghrelin

• satiety - insulin, leptin, CCK

which macronutrient is the strongest promoter of satiety

protein

what make sup the enteric nervous system

submucosal plexus and myenteric plexus

know what stimulates acinar and ductal cells of the pancreas, what they release and why they are important

stimulated by CCK

• release bicarbonate

describe the functions of the liver

• synthesis

• conversion

• storage

describe the function of bile

breaks down large fat globules into smaller ones allowing larger surface for digestion

what is the difference between a bile salt and bile acid

bile salts are amphipathic

describe functions of the liver

• synthesis

• conversion

• storage

know the pathway for enterohepatic circulation

liver, gallbladder, pancreas, duodenum, jejunum, ileum, portal vein

what stimulates motility in the large intestine

acetylcholine from enteric nerves

what is colonic salvage

fermentation

know important factors in the development of the gut microbiome

• developed in first 2 years

• style of birth

• breastfed vs formula

• complementary food introduction

• antibiotics

• environmental exposure

what are probiotics and prebiotics

• prebiotics - food for good bacteria

• probiotics - live strains of microorganism

explain the 4 absorption mechanisms

• passive

• facilitated

• active

• endocytosis

describe transport of polar and nonpolar substances following absorption

• polar - go through portal vein and to liver

• non polar - go through sympathetic system