Metabolism Flashcards
What is the purpose of metabolism?
Metabolism is a set of chemical reactions that transforms food into energy for cellular activities and build organic molecules necessary for life
Why do cells need to synthesize new organic components?
Cells require new organic components for growth, repair, and maintenance of cellular structures and function
Why do cells need to break down components?
Breaking down components release energy that cells use for various biological processes
What type of reaction are involved in synthesizing new organic molecules? are these reactions energy-consuming or generating?
Synthesis reactions require energy input to build complex molecules
* ex: Anabolic metabolism
what type of reactions are involved in breaking down organic molecules? Do these reactions consume or generate energy?
Break down reactions release energy and are known as catabolic metabolism
Why is energy necessary for cells?
Energy is important for active transport, enzymatic reactions, muscle contraction, and various other cellular processes
What is the unit energy used in biological system called?
ATP (adenosine triphosphate)
What is glycolysis?
Metabolic pathway that breaks down glucose into pyruvate
Where does glycolysis occur?
It occurs in the cytoplasm of the cell
What molecules are required during glycolysis?
Glucose and ATP
What is the overall energy yield of glycolysis?
Glycolysis produces a net gain of 2 ATP molecules per glucose molecule
How many ATP molecules are used/ consumed during the process of glycolysis?
2 ATP molecules are used during the energy investment phase of glycolysis
How many ATP molecules are generated/consumed during the process of glycolysis?
4 ATP molecules are produced during energy playoff phase , but 2 ATP were initially used, resulting in a net gain of 2 ATP
How many NADH molecules are produced/used during glycolysis?
2 NADH molecules are produced
List the end products of glycolysis
2 Pyruvate molecules, 2 ATP, 2 NADH molecules
What happenes to NADH produced during glycolysis?
NADH enters mitochondria and participates in the Electron Transport System (ETS) to generate ATP
What is anaerobic respiration?
Anaerobic respiration occurs in the absence of oxygen + involves processes like fermentation. it produces products like **lactic acid or ethanol **and occurs in the cytoplasm
What is the importance of the 1st phosphorylation step in glycolysis?
Phosphorylation of glucose traps it inside the cell and prepares it for further metabolic breakdown
What is aerobic respiration?
Aerobic respiration occurs in the presence of oxygen + involves glycolysis, the citric cycle, and the electron transport chain. it produces CO2, H2O, and lots of ATP
Steps of glycolysis
- Glucose is modified by adding a phosphate group to carbon number 6
- Another phosphate group is added to carbon number 1 of glucose
- Glucose molecule is split into 2 smaller 3-carbon molecules
- Each of the 3-carbon molecules goes through a series of reaction + is converted into pyruvic acid. During this process each 3-carbon molecules produces 2 ATP and 1 NADH
Since there are two 3-carbon molecules, the total ATP produced is 4 + the total NADH produced is 2
Mitochondria
- Double membraned organelles
- Inner membranes form folds called cristae, and its the site for oxidative phosphorylation
- Produce ATP (powerhouse of cells)
Which metabolic process occurs in mitochondria? what is the purpose of these processes?
Involved in TCA cycle, oxidative phosphorylation, and the breakdown of fatty acids
these processes** generate ATP** through efficient oxidation of glucose and other energy-rich molecules
Which byproducts of glucose metabolism enters mitochondria?
Pyruvate, the byproduct of glycolysis, enters mitochondria for further metabolism
Why doesn’t glucose enter mitochondria directly and is metabolized into pyruvate inside mitochondria?
Pyruvate serves as an intermediate that can be further broken down in the TCA cycle. The conversion of glucose to pyruvate allows for controlled energy extraction.
Explain the process that occurs during the intermediate/transition step.
Pyruvic acid is converted into Acetyl CoA during this step, releasing CO2 + producing NADH
What is the Intermediate/Transition Step?
transports Pyruvic asid into mitochondria for further breakdown
WHat does pyruvic acid combine with and form Acetyl CoA
Pyruvic acid combines with **CoA **to form Acetyl CoA
Input molecules: Pyruvic acid, CoA
Output molecules: Acetyl CoA, CO2, NADH
What is TCA Cycle ?
Series of chem reactions that oxidize acetyl group derived from nutrients to produce energy
TCS cycle begins with the formation of which molecules?
Citric acid from acetyl CoA + oxaloacetate
What is decarboxylation + why are the chem reactions during the process of TCA referred to as decarboxylation reaction?
Decarboxylation involves the removal of CO2 molecules.
In TCA, CO2 is removed during specific steps, leading to formation of energy rich compounds
What is oxidative phosphorylation?
Process of generating ATP from the flow of electron transport chains (ETS) + phosphorylation of ADP to ATP
How many times must the TCA cycle turn to break down the pyruvic acid produced by 1 molecule of glucose?
The TCA cycle turns twice for each glucose molecule, as 2 pyruvic acid molecules are produced during glycolysis
What is the role of NAD + FAD in the TCA cycle?
NAD + FAD act as coenzymes, accepting hydrogen atoms during decarboxylation reactions + carrying them to the electron transport chain for ATP synthesis
Is most of ATP directly produced during the TCA cycle?
NO most of the ATP is generated indirectly through the electron transport chain (ETS) where NADH + FADH2 transfer e- , leading to ATP production
What is ETS?
Chain of proteins (cytochromes) in the inner mitochondria membrane.
* these proteins accept e- from NADH/FADH2, transferring them along the chain + releasing energy. ultimately O2 accepts the e-, forming H2O
How many hydrogen atoms are pumped into intermembrane space of the mitochondria by 1 NADH during the process of ETS?
1 NADH molecule pumps **10 hydrogen **atoms into intermembrane space
What happens to the hydrogen ions pumped into the intermembrane space?
Hydrogen ions flow back into mitochondrial matrix through ATP synthase, driving the synthesis of ATP
How many molecules of ATP are produced for every pair of hydrogen atoms passing through the ATP synthase gate to mitochondrial matrix?
3 molecules of ATP
what occurs as hydrogen enters the mitochondrial matrix?
Hydrogen ions combine with e- + O2 to form H2O in mitochondrial matrix
What is oxidation?
Process of losing e- or gaining O2
Involves a substance losing hydrogen atoms
What is reduction?
Process of gaining e- or losing O2
Involves a substance gaining hydrogen atoms
Is NADH/FADH2 an oxidized or reduced form of the molecule?
Reduced form of the molecule as they carry e- + hydrogen atoms
Glycogenesis (-genesis= production)
Synthesis of glycogen
Glycogenolysis (-lysis= breakdown)
Breaking down glycogen
Glycolysis
Conversion of glucose to pyruvate
Gluconeogenesis
Converting pyruvate to glucose
Total # of ATP/NADH/FADH/GTP/CO2/H2O produced during GLYCOLYSIS?
2 ATP
2 NADH
Total # of ATP/NADH/FADH/GTP/CO2/H2O produced during THE INTERMEDIAT STEP?
2 NADH
Total # of ATP/NADH/FADH/GTP/CO2/H2O produced during TCA cycle
2 GTP
6 NADH
2 FADH2
Total # of ATP/NADH/FADH/GTP/CO2/H2O produced during ETS
Converts NADH/FADH2 to ATP + 1 NADH produces 3 ATP
What happens to the molecules of NADH + FADH2 produced during glycolysis; the intermediate step; TCA; and ETS?
NADH + FADH2 carry e- to the electron transport chain in the mitochondria, where they are used to generate ATP
What is lipolysis?
Breakdown of triglyceride into glycerol + fatty acid, making stored fats accessible for energy production
What is beta-oxidation?
Process where fatty acid are broken down into 2-carbon fragments (acetyl-CoA) in mitochondria
Which molecules are generated during the process of beta-oxidation ?
Acetyl-CoA
NADH
FADH
How many ATP are generated by 1 round of beta-oxidation?
12 ATP from Acetyl-CoA
3 ATP from NADH
2 ATP from FADH
How many ATP does Acetyl-CoA generate? Explain
12 ATP
In Krebs cycle it produces 3 NADH (3 ATP), 1FADH2 (2 ATP), and 1 GTP (1 ATP)
Does 1 molecule of fat or 1 molecule of glucose generate more ATP?
1 molecule of fat generates more ATP than 1 molecule of glucose
When do lipids provide energy?
During modest + slow physical activities b/c they require more O2 to metabolize efficiently
When are lipids used as a source of energy?
When glucose reserves are limited
- during fasting or low carbohydrate intake
What are essential fatty acids?
Fats that the body cannot produce + must be obtained from diet
- omega-3 + omega-6 fatty acids
How are non-essential fatty acids synthesized?
Through lipogenesis, starting with Acetyl-CoA, which can be converted to various molecules
Explain the steps of fats/lipid transport + distribution
Lipids are transported from intestine to liver as chylomicrons
Triglycerides are transported from the liver to cells via very-low-density lipoproteins (VLDL).
Cholesterol is transported from the liver to cells via low-density lipoproteins (LDL).
Excess cholesterol is transported from cells back to the liver via high-density lipoproteins (HDL)
Lipoproteins containing triglyceride produces in the liver + transporting them to peripheral tissues (cells) are called…
Very-low density lipoproteins (VLDL)
Lipoproteins that transport most cholesterol from tissues/cells to liver are called…
Low-density-lipoproteins (LDL)
Lipoproteins that transport cholesterol to peripheral tissues/cells are called…
High-density lipoproteins (HDL)
What is lipogenesis?
Process of synthesizing fats from simpler molecules, including Acetyl-CoA
What is Transamitation
Transferring an amino group from 1 amino acid to a keto acid, creating new amino acid
- glutamic acid converted into tyrosine
What is deamination?
Removing an amino group from an amino acid, leading to the production of ammonia
Where is Urea formed
In the liver as a result of combination of ammonia + CO2, and its excreted by the kidney
What are essential + nonessential amino acids?
Essential amino acids CANNOT be synthesized by the body + must be obtained from diet
Nonessential amino acids CAN be produced by the body
What are some fat soluble vitamins?
Vitamin A, D, E, K
Name a mineral/atom important in hemoglobin/cytochrome/myoglobin proteins?
Iron (Fe)
Name a mineral important in bone growth + maintenance?
Calcium (Ca)
Name vitamins that are important for vision, bone growth, and calcium absorption?
Vision: Vitamin A
Bone Growth + calcium absorption: Vitamin D
