(Physiology) - Metabolism and DNA replication Flashcards
Metabolism and Exercise
what it ATP turned into and why
what happens if ATP is too high
Available energy sources for a muscle cell include
Too high ATP turn off phosphofructokinase
Ready ATP turn into Creatine phosphate (“storage form” of ATP)——- so ATP production is not turned off
Blood plasma glucose
Glycogen in liver and muscle (storage)
———-Gluconeogenesis (liver)
Fatty acids (diet / storage)
Fat as fuel
how does it break down
efficiency?
is it used right away?
Uses beta-oxidation to form acetyl CoA
break down big long fatty acid chain and cutting off into 2 carbon units8
Then enters TCA cycle
High energy yield
Most efficient storage of energy
Beta oxidation is slow to start – not used initially
————————————-
Fats to fatty acids- they come in in the TCA
glycerol to pyruvate
High Protein – Low Carb Diets
how much energy does it take to digest
ATP yield?
do you feel hungry or full on this diet and why?
Protein metabolism uses a lot of ATP and takes a lot of energy to digest
- Less overall ATP yield
With low carbs – must turn to fat metabolism
High fat intake
Keeps you feeling fuller longer
* Releases leptin hormone = “fullness”
proteins as fuel
how are they broken down
ATP yield?
when do we use them for energy?
Amino acids converted to ketoacids
Low overall ATP yield
Last resort for energy
Eg. Starvation
Or high protein intake
Overview of Muscle Metabolism
steps to ATP fast
- why shouldn’t ATP buildup in cell
- how does it counteract that
why do we need ATP in muscle
storage of glycogen-into glucose- go thur glycolysis- get pyruvate and Acetyl CoA- oxidative metabolism- PRODUCES ATP
DONT WANT IT TO BUILD UP
Convert ATP into creatine phosphate
hides ATP so metabolism keeps going and whenever need turn creatine phosphate into ATP
For contraction AND relaxation(myosin heads)
Energy Systems in Exercise
time
what does the graph look like
First thing we do when we get up off couch
trigger PHOSPHAGEN system
that is the creatine phosphate and ATP
FIRST 5 TO 10 SECONDS
————————————————————
Also turn on glycolysis right away- sugar-glycogen
2-3 minutes, anaerobic glucose metabolism
———————————————-
once you are breathing hard enough and provide enough oxygen to cell to use aerobic metabolism
TCA cycle, glucose, amino acids and fatty acids- 5 minutes
Structure of DNA
5 prime and 3 prime
double helix
polymer of nucleotides
nitrogenous base, sugar, phosphate
5’ end, phosphate on it. Ph-Ph
3’ end , where ribose is
DNA set up and make up
base pairs
line up antiparrelel
bind at nitrogenous bases.
2 ring with a 3 ring
Apple in the Tree
Car in the Garage
Adenine to Thymine- 2 rings
Cytosine to Guanine-3 rings
Semi conservative DNA replication
Parent unwinds
Two daughters built; Base pairing rules
base pairs connect with each other
each daughter contains one parents strand
DNA replication steps
0) It begins when a complex protein molecule binds to THE POINT OF ORIGIN and forms a replication bubble separating the two strands
1)Topoisomerase uncoils DNA
2)1) helicase separates the DNA strands
3) primase creates RNA primer, allows polyIII to bind
4) The leading strand is synthesized by polyIII 5’to3’ direction
5) DNA polymerase I (RNase H) removes the primers
6) ligase joins the Okazaki fragments of the lagging
Difference between the two strands during replication
Lagging:
– - - - the 5’ end is exposed so doesn’t grow towards the old DNA, grows away from fork
- - – gaps because RNA Primer is needed. RNA primer is needed and Poly III
- - – 5’ to 3’ side is whats left but must build in 3’ to 5’
- - – EACH Okazak i fragment must be primed
—— polymerase I replaces Primer on BOTH
Leading:
- - - -The 3’ end is exposed so it grows towards the old DNA continuously.
- – - from 3’ end to 5’end is left, but builds as 5’ to 3’
– - one primer and works forever
Steps Again
what order or way does poly III add nucleotides
0) topoisomerase unwinds helix
1) Helicase separates DNA strands helix
2) primase puts on an RNA primer
3) DNA polymerase III elongates the strand and adds nucleotide only to 3’ end. Reads 3’ to 5’, builds 5’ to 3’
4) DNA polymerase I removes primers
5) ligase fills in gaps
Proof Reading DNA replication
any wrong nucleotides
polymerase II can cut and paste the right one in, same if nucleotides are damaged
and ligase will do final glue job
Repeated Replications
are we losing DNA
what is at the end
what is the enzyme to stop us from losing
every time we replicate DNA we need primer
lose nucleotides because we lose primer
so daughter molecules get repeatedly shorter
Junk DNA, telomeres, contains genes, and deletes genes
In stem cells, blood cells, gametes, telomerase lengthens telomeres, to protect genes on inside
