Carbs and Lipids Flashcards
Carbohydrates
structure of all carbs
glucose
disaccharides
polysaccharides
Carbs: 1:2:1 ratio of carbone, hydrogen, oxygen
examples: sugars, starches and glucose
the C-H bond holds lots of energy: breaking of this bond via water releases the energy!
thus, C-H formation is a good energy storage
Glucose
- a monosaccharide = meaning a single sugar
- 6 carbons
- structural isomers: fructose & galactose
Disaccharides
- 2 monosaccharides together linked via dehydration synthesis
- used as sugar storage or transport
- examples = sucrose, lactose and maltose
polysaccharides
- longer chains of sugars; used for energy storage within plants and animals
- plants = use starch
- animals = use glycogen
- used for strucutral support too!
- platn + structure = cellulose
- animals + structure = chitin
Explain the process of high blood glucose & how it goes to the cells for energy use
high blod glucose
triggers insulin release
insulin binds to cells: allowing the cells to take in teh free glucose from the blood
skeletal muscle: takes in glucose = makes glycogen & takes in amino acids = makes proteins
adipose tissues: store gluose as triglycerides
liver: stores glucose as triglycerides or glycogen
Briefly, explain the overview of how glucose is used for energy (glycolysis, CAC, anaerobic and aerobic conditions
Glucos —> 2 pyruvate
- the process of glycolysis occurs INDEPENDTLY of oyxgen; not needed
- releases energy and produces pyruvate
Pyruvate —> Acetyl CoA & CAC
- releasing more energy (atp) as a result of breakdown
- the CAC can only occur under aerobic conditions: meaning oxygen must be present
- this produces the maximum amount of energy from the orignal products
Anaerobic Conditions
- fermentation to ethanol (not important here)
- fermentation to lactate and the build up of lactae = lactic acid & subsequent metabolic acidosis & sepsis
Glycolysis
- what goes in
- what comes out
- how many stages
- where does they pyruvate product go
Glycolysis: first step of glucose breakdown
- 1 glucose molecule spilt into 2 pyruvate molecules
- free energy is released - ATP/NADH
- this is a sudden burst of energy production, which does NOT require oxygen
Stages
- 2 -10step stages of glycolysis produces in the end 2 ATP
Under aerboci conditions (oxygen present) = these pyruvates wil contiue to the CAC and create more ATP (most energy)
under anaerobic conditions (no oxygen present) = these pyrvuate will convert to lactate
Gluconeogenesis
where does it occur
how is it different
what are the precursor molecules
Gluconeogensis: making new glucose
- this cannot jsut be the reversed process of glycolysis because the processes is irrerversible in nature
Where does this occur
- majority in the liver
- kidneys (minor)
- small intestine (in specific instances)
Gluconeogenesis is triggered by glucagon- and its the process of making glucose from NONcarbohydrate precursors
Precusors for gluconeogenesis
- lactate
- pyruvate
- glycerol (from fat)
- amino acids
during fasting conditions: gluconeogenesis is responsible for almost all the bodies production of glucose
the role and vital need for glucose in the body
- the brain
- the red blood cells
all cells need and depend on glucose
the Brain: sensitive to glucose chagnes in teh serum, requires tons of glucose daily
the red blood cells: survive only on glucose
during fasting: glycogen (the sotred form of glucose) in the liver is mobilized to begin its breakdown to supply the body (but this supply could ony allow for 12-24hours)
if needing more glucose thatn that; cells resort to making new glucose from smaller noncarb. sources
Glycogenolysis
- what is it
- what is its role
- how is it activated
Glycogenolysis: the breakdown of glycogen (the storage form of glucose) into glucose
Triggered by
- glucagon release from pancreas (triggers liver to start glycogenolysis) as a result of low blood glucose
- epinephrine triggers glycogen breakdown in the muscle cells
this pathways turns glycogen into glucose
but remeber, the stored glucose as glycogen wont last us long in fasting, so gluconeogenesis is the main energy form in fasting
Lipids
what are they
chemical bonds
4 major roles in the body
two categories and how they differ
Lipids: insoluable in water
- a high proportion of C-H nonpolar bonds causes hydrophobic connections
Categories
- Fats (triglycerides)
- Phospholipids
4 Roles in the Body
- structural components of biological membranes
- energy reserves: as triglycerols
- lipids and lipid derivitives are vitamins and hormones
- lipophilic bile acid help with lipid soluablitiy (from diet)
Triglycerides
- main role
- strucutre and function relationship
Triglycerides: energy storage molecule: store 2x as much energy than carbs do
Animal Fats: saturated fats & solid at room temp.
- saturated: single bonds
Plant Fats (oils): unsaturated fats & liquid at room temp.
- unsaturated = double bonds
How are lipids synthesized
fatty acids (the long chains) are converted to triglycerides (storage molecule), degrated when needed for energy and can be used in the membrane synthesis
- when serum glucose is high; insulin promotes triglyceride snythesis by promoting glucose uptake into adipocytes: lipogenesis
- adipocytes cannoy synthesize triglycerides when glucose levels are low, or when hormones stimulate lipolysis: or breakdown of the triglycerides via hydrolysis to form glycerol and fatty acids
- when tebody is under stress and needs every: glucagon and epi. are released and these trigger the activaition of cAMP and therefore breakdwon tryglycerides into glycerol and FFAs
Phospholipids
what are they used for (4 major)
what do they contain
how do they form structures
Phospholipids : lipids which form cell membranes and bilayers
Contain
- glycerol head
- 2 fatty acid tails
- a phosphate group
- heads: polar and good with water
- tails: nonpolar: hate water
Formation
- form micelles: single layer
- form bilayers: two layers
Uses
- formation o structural components of the membrane
- emulsifying agens and surface active agents
- amphipathic moelcules (2 ends)
- phosphoglycerides & spingomyelins (nerves)
How are Complex Lipids Metabolized (aka steroids)
- structure
- where are they found
- normal level in seurm & attached to what
Steroids:
- contain a steroid ring which cannot be broken apart
- it is non saponifiable
- this is the main tissue of animals, and found in brain,erve and glands
maincomponent of glalstones
normal levels in teh serum (200)
- steroids in teh serum must be bound to proteins - aka HDL,LDL, etc. = lipoproteins
What are Lipoproteins
Lipoproteins: proteins which covalently link to lipids found within the body
plasma lipoprotiens ae the transport system for lipids throughout the boyd: whether its steroids or triglyerols
- the name of the lipoprotein depends on the density
Chylomicrons: Largest, least dense lipoprotein, transport dietary triglycerols and cholyesterl esters from intestines to tissue
VLDL: syntehsized in the liver; transport lipid to tissue; converted to LDL when they lose a triglycerol, an apoprpotein or phospholipid
LDL: carry cholesterol to tissue; engulfed by cells after binding to their LDL receptors to bring them in
HDL: highest density: produced in the liver; scavange up the cholesterol from cell membranes as cholestrol esters, trasnported to the liver & excess cholesterol is disposed as bile acid
lipoproteins
- phospholipid outer later
- choelsterol and steroids at teh core in teh middle to be trasnported around
Role of lipoproteins and dyslipidemia
treatment target
25% of adults have dyslipidemia
- 85% with CHD have dyslipidemia
- strong family predisposition to this!!!
direct relationship: increased LDL and decreased HDL both indirectly related and correlated to the risk of having CHD
Treatment
- triglycerides: pro-inflammatory and pro-thrombotic
- therefore, they increase fiberinogen (clot), increas clotting factors and increase viscosity of blood
- all these increaes one’srisk fo CAD, CVE, PE, DVT
