Lesson 12 - Cell functions (29 - 57) Flashcards
Protiens as a fuel
Amino acid is converted to ketoacids
This gives low ATP yield, as does not give much ATP and you have to convert it
Last resort for energy, starvation/high protein intake
depends where slides into pathway/citric acid cycle
Fat as fuel
Uses beta-oxidation for form acetyl CoA
-takes long chain of fatty acids and cut them into carbon units (two)
-then enter TCA cycle
High energy yield, lots of ATP
Most efficient storage of energy
20 carbon fatty acid chain makes 10 acetyl CoA
Beta oxidation is slow to start, not used initially
Fuel
Glucose = quick to start, good but temporary yield
Protein= better for something else but last resort
Fat=good yield but takes longer to get up and running
High protein low carb diets
protein metabolism uses a lot of ATP
-less overall atp yield
-with low carbs- must turn to fat metabolism as you don’t have regular fat access
High fat intake
-keeps you feeling fuller for longer
-releases leptin hormone =fullness
Energy Systems in exercise
Immediate: Phosphagen (creatine phosphate and ATP). 4 mole of ATP/min
5-10 sec to fatigue
Short term: Glycolysis (glucose). 2.5 mole of ATP/min. 1-2 min to fatigue
Long term: Aerobic, TCA cycle (glucose, amino acid, fatty acid). 1 mole of ATP/min. 2 min + unlimited time to fatigue
Metabolism and exercise
Available energy sources for a muscle cell include
-Ready ATP
-Creatine phosphate (stored ATP)
- Blood plasma glucose
- Glycogen in liver and muscle
- Glucogenesis (liver) (glucose made from other things like amino acids)
- Fatty acids (diet/storage)
DNA replication and structure
Needed for mitosis and meiosis
-S phase
DNA
-double helixed molecule
DNA
Polymer of nucleotides
Nucleotide has: nitrogenous base, sugar and a phosphate group
-Two anti parallel sugar phosphate backbone
- 5 prime left, 3 prime end right
Nitrogenous bases are paired in molecules interior with a hydrogen bone
A+T= two h bond
C+G = 3 h bond
DNA replication
Each strand acts as a template for a building of a new stand
Parent unwinds, Two daughters built, base pairing
Semi conservative because each daughter has 1 parent strand
Overview
- Bubble forms with a replication fork for two daughter strands to form
- Helicase unwinds the double helix
- Topoisomerase stabilizes over twist ahead of helicaase
- Primase, primes strands with RNA
5.DNA polymerase III reads the strand (parent) from 3-5 and builds the daughter from 5-3. Can only read in one direction
- DNA polymerase I replacesRNA primer with DNA, nucleotides
- Ligase ties it together
Lead strand
Synthesizes a complementary strand continuously
-moving toward replication fork
-Primase adds RNA primer once
- DNA polymerase III builds continuously, Polymerase I replaces primer
-Ligase binds it other segment
Lagging strand
Synthesizes a series of segments, open up do a chunk
-these are called Okazaki fragments
-joined together by DNA ligase
-moves away from replication fork
Primase adds short primer sequences
DNA polymerase III adds nucleotides to 3’ end until it reaches primer
DNA polymerase I replaces primer nucleotides with DNA
Liagase bonds segments together
Enzymes
Helices - unwinds helix
Topoisomerase- stabilizes the untwist, making it easier
Primase- adds primer to strand
DNA polymerase III - reads strand from 3’-5 (parent)
DNA polymerase I - replaces primer RNA
Ligase-glues/ties strand together
Primers
DNA polymerase cannot imitate synthesis of polynucleotide. Polymerase III needs to attach to primer first
Initiated by RNA or DNA primer
-short nucleotide strand
Lead strand needs one primer while laying needs multiple (Okazaki fragment)
Proof-reading/ mismatch repair
-enzymes cut out and replace damaged stretches of DNA
-Polymerase II makes readings and cuts
ex: damage from sun
