Metabolism (Exam 3) Flashcards
define metabolism
all chemical reactions in the body
Enzymes do what?
lower the activation energy of a rxn
ana-
to build up
cata-
to break down
What organelle is known as the workhorse of the cell?
the mitochondria
ATP = ?
energy
Adenosine is what?
a sugar
when phosphate group has been removed…
… battery has been used
All chemical bonds represent…
… a potential available energy
define phosphorylation
to add a phosphate
what are the two types of phosphorylation?
Substrate level phosphorylation and oxidative phosphorylation
what is substrate level phosphorylation
when phosphate is transferred directly from substrate to ADP via an enzyme
what type of phosphorylation provides more E
oxidative phosphorylation (involves sugars)
what is oxidative phosphorylation?
the electron transport chain
in cellular respiration, one sugar equates to what yield of ATP/glucose?
one sugar equates to max yield of 36-38 ATP/glucose
LEO
Loss of Electrons = Oxidation
GER
Gain of Electrons = Reduction
NAD without H means
battery is not charged
what is a coenzyme?
a molecule that has to be present for an enzyme to work
do coenzymes get used up?
no, they only aid the main enzyme
What four things is glucose used for?
ATP Production
Amino acid synthesis
glycogenesis
lipogenesis
where is glycogen stored?
stored in liver and skeletal muscle
Glucose moves into cells via what method?
facilitated diffusion
GluT transporters are the passive transporters and insulin acts as a key to unlock GluT transporters at the site of the cell
Glucose is provided by…
the diet
Glucose catabolism is also known as
cellular/aerobic respiration
What exactly is glucose catabolism/cellular/aerobic respiration?
It is the oxidation of glucose to produce ATP
What are the 4 main stages of glucose catabolism (or cellular/aerobic respiration)?
glycolysis
Pre-Krebs/Acetyl Co-A formation
Krebs Cycle
Electron Transport Chain reactions
Glucose + 6 Oxygen yields…
6 Carbon Dioxides + 6 Waters
Where does glycolysis take place in the cell?
in the cytosol
What pathway is glycolysis a part of? Anaerobic or aerobic?
can be done anaerobically, but part of both pathways
What molecule does glycolysis start with and what molecule does it finish with?
Starts with glucose, ends with 2 molecules of pyruvic acid
In glycolysis, how many ATP are produced by substrate level phosphorylation?
4 ATP are produced, but two of the 4 are used in the process so the net gain is actually 2 ATP
In glycolysis, how many of the hydrogen carriers (NADH or FADH2) are being produced?
2 NADH
Name the two hydrogen carriers
NADH and FADH2
From what process are pyruvic acids produced?
glycolysis
What does pyruvic acid convert to?
lactic acid
What is lactic acid fermentation useful for?
It helps regenerate NAD+
Acetyl Co-A formation leads up to…
the Krebs Cycle
Where does Acetyl Co-A formation take place?
in the mitochondria
What pathway is Acetyl Co-A formation a part of?
aerobic
What molecule does acetyl Co-A formation begin with and what molecule does it end with?
Begins with pyruvic acid, ends with Acetyl Co-A
In acetyl Co-A formation, how many ATP are produced by substrate level phosphorylation?
0
In acetyl co-A formation, how many hydrogen carriers are produced?
One NADH per each pyruvic acid, which is a total of 2
2 NADH = how many ATP
6 ATP
What does Coenzyme A do?
it transports the acetyl group into the Krebs Cycle
CO2 is a waste product of what?
cellular respiration
In order for the acetyl group to be transported to the Krebs Cycle, what must be present?
Acetyl Coenzyme-A
What is the Krebs cycle also known as?
The citric acid cycle
Where does the Krebs cycle take place?
in the mitochondria, deep in the matrix
What pathway is the Krebs cycle a part of?
aerobic
What molecule does the Krebs cycle begin with and what molecule does it end with
Begins with acetyl CoA which combines with oxaloacetate to create citric acid
In the Krebs cycle, How many ATP are produced by substrate level phosphorylation?
1 ATP per cycle, however, there are 2 Krebs cycles running per glucose so 2 Total
In the Krebs cycle, how many hydrogen carriers are produced per each acetyl Co-A?
3 NADH (6 per glucose) = 18 ATP 1 FADH2 (2 per glucose) = 4 ATP 1 ATP (2 per glucose)
What is the final and most important step of cellular respiration?
the electron transport chain
The electron transport chain is part of …
oxidative phosporylation
What is the electron transport chain?
a series of integral proteins on the inner membrane of the mitochondria known as electron carriers
In the electron transport chain, what allows us to pump protons through the membrane?
the electron flow
Membranes let things through unless it is…
large or charged
ATP synthase does what?
synthesizes ATP
Synthase is powered by
protons
what powers proton pumps?
electron flow
What are the 3 processes under glucose anabolism?
Glycogenesis
glycogenolysis
gluconeogenesis
gluconeogenesis is…
the conversion of amino acids, lactic acids and glycerol
usually a sign of malnutrition
does fat dissolve in water?
no, it is hydrophobic
lipids bind to…
proteins
what do chylomicrons do?
they transport dietary lipids
What are the four lipoproteins?
chylomicrons
VLDL
LDL
HDL
What is VLDL and what does it do
Very Low Density Lipoprotein; picks up lipids out of the liver
transports lipids formed in hepatocytes
What is LDL and what does it do?
Low Density Lipoprotein; delivers cholesterol to the cells
known as the “bad” cholesterol
What is HDL and what does it do?
High Density Lipoprotein; it removes excess cholesterol from the cells
known as “good” cholesterol
Is high LDL and HDL bad?
No, so long as the ratio is even
what is lipolysis?
the breakdown of lipids
what does beta oxidation do?
it breaks down fatty acids and forms acetyl CoA
what is ketogenesis?
it is the formation of ketone bodies from fatty acid metabolism
what is lipogenesis stimulated by?
insulin
**insulin levels rise after a meal
what is lipogenesis
the conversion of excess glucose, aminos, and fatty acids
what is catabolism referred to in reference to protein metabolism?
Deamination
What three things happen in deamination?
the amino group is removed
the aminoless molecule enters Krebs Cycle
The Amino group becomes ammonia and is converted to urea
How many amino acids are needed for protein anabolism?
total of 20
10 essential
10 nonessential
