Biomolecules Flashcards
What is OXIDIZED in the cell to generate ATP (3)?
Carbohydrates, fats, and proteins
What happens to electrons during oxidation?
loss of electrons
What happens to electrons during reduction?
gain of electrons
Where does initial glycolysis occur?
Cytoplasm
Where does remaining glycolysis occur?
the inner membrane of the mitochondria
What are the byproducts of cellular metabolism (4)?
CO2, H2O, energy (ATP), and heat
How many calories and ATP is generated from 1 mole of glucose?
1 mole of glucose (180 g) generates 686,000 calories to get 36-38 moles of ATP (each ATP requires 12K calories= 456,000 calories)
What is a calorie?
unit of energy, the energy thatisneeded to increase the temperatureof1 gofwater by 1C at one atmosphere
What is kilocalorie?
isthe energy thatisneeded to increase the temperatureof1 kgofwater by 1C
What is adenosine triphosphate?
Organic compound, ”molecular unit of currency/energy” for the body that drives MANY of the biologic processes in the body
When is a majority of ATP used?
Much used during protein synthesis to form peptide linkages between amino acids
How is ATP normally stored?
ATP itself not stored- the high energy phosphate molecules are stored as phosphocreatine within the cell (provide the buffer source to quickly “charge” ATP from ADP/AMP)
How is ATP produced (3)?
Produced by glycolysis, oxidative phosphorylation (Citric Acid Cycle/Kreb’s) and beta oxidation (fatty acids used as fuel)
What is ATP a precursor to (2)?
DNA/RNA , second messenger cAMP
What is ATP classified as?
nucleotide triphosphate: nitrogen base (adenine), sugar (ribose) and triphosphate
What is the formula of ATP?
ATP ↔️ ADP + PO3 + ⚡️ ↔️ AMP + PO3 + ⚡️
Dephosphorylation/hydrolysis of ATP by enzymes ATPases
How many kcal/day are required to meet basic metabolic needs? How many oxygen?
20 kcal/day; 250 mL/min of oxygen
What is the average kcal/kg for men? Women?
Men on average: total 39 kcal/kg; Females 34 kcal/kg
How many kcal/g are founded in carbohydrates/proteins; fats; alcohol?
Carbohydrates/proteins provide 4.1 kcal/g; fats 9.3 kcal/g; alcohol 7 kcal/g
What is the structure of carbohydrates?
Carbon compounds with large quantities of hydroxyl groups (OH), often referred to as “sugars” or saccharides
What is monoasaccharides?
the simplest carbohydrates, are polyalcohol aldehydes or ketones that have two or more hydroxyl groups vs polysaccharides (very large)
Why is monosaccharides important?
Are important fuel molecules as well as building blocks for nucleic acids. Hexoses.
Monosaccharides are ______
water soluble
What are examples of carbohydrates (4)?
- Glucose (Glycogen)
- Fructose
- Galactose
- Ribose
What is ribose?
the carbohydrate component ofthe nucleic acids- 5 C molecule
What is the most important disaccharides for human biology?
Sucrose, Lactose and Maltose
What is sucrose?
glucose and fructose
What is lactose?
glucose and galactose
What is maltose?
2 glucose molecules
How are disaccharides broken down?
Broken down into monosaccharides in the small intestines and carried to the liver via the portal vein
What is the site of carbohydrate metabolism?
Liver is the site of carbohydrate metabolism: regulation, storage (glycogen), conversion of glucose from galactose/fructose, which produce same amount of energy
What is glucose?
the predominant (not only) source to produce ATP
What is glycogen?
Long polymers similar to starch: how glucose stored (not stored in its free form)
How much glycogen is stored?
Up to 90% of the glucose from a meal can be stored as glycogen
Why is glycogen released?
Released during fasting from the liver and strenuous exercise from muscle
What is glycogen phosphorylase?
Enzyme: glycogen phosphorylase converts glycogen to glucose derivatives (glucose-1-phosphate)
What are examples of lipids?
waxes, sterols, fat-soluble vitamins, triglycerides (fat), phospholipids, and other substances
What type of organic molecules are lipids?
Hydrophobic
What are fatty acids?
carboxylic acids- long chains that can be saturated/unsaturated
How are lipids absorbed?
from the GI tract as chylomicrons via lymph system
How are lipids removed from circulation?
From tissues (adipose, liver, skeletal, heart) via lipoprotein lipase
What is lipoprotein lipase?
extracellular enzyme- allows free fatty acid across cell membrane
What are chylomicrons?
Consist of phospholipid and apolipoproteins on the outer surface and triglycerides and cholesterol (vary in size) inside
What is cholesterol?
is considered a lipid although does not contain fatty acids (cell membrane, hormones) Hydrocarbon rings. Sterol.
What is lipoproteins?
are part lipid, part protein
How is lipoproteins synthesized?
Synthesized by hepatocytes
What is VLDL and LDL?
contains most of the cholesterol in plasma
What is HDL?
sends excess cholesterol from the peripheral tissue back to the liver to be excreted in bile
What are triglycerides?
tremendous source of energy- liberated as 3 fatty acids and glycerol
How are triglycerides liberated?
hydrolysis from adipose and carried to cells by mainly by VLDL and albumin (lipase)
What stimulates triglycerides?
low glucose levels
What is the back bones of triglycerides?
Glycerol is a sugar alcohol that binds fatty acids together
What is the functions of triglycerides (2)?
Either used as fuel or restored as triglycerides
What are examples of triglycerides (2)?
Tristearin and Glycerol
Are fatty acids the same as fats?
No
What are saturated fatty acids?
have carbon chains that contain only carbon-carbon single bonds (close carbon bonds resistant to enzymatic activity)
What are unsaturated fatty acids?
have carbon chains that contain at least one carbon-carbon double bond
What are essential fatty acids?
must be consumed, essential for biological functions
What are the types of phospholipids (3)?
lecithin, cephalins, sphingomyelin