Chemistry Of Life Flashcards
Four main classes of macromolecules present in cells
- Carbohydrates (made of sugars)
- Proteins (made of amino acids)
- Nucleic acids (made of nucleotides)
- Lipids (fats, phospholipids, and steroids)
Carbohydrates are composed of ____ and can be classified into (4)
-composed of C, H, and O
Classified into:
-Fibre
-Starch
-Polysaccharide (complex sugars)
-Monosaccharides (simple sugars)
Glycogen is
A polysaccharide used for storage in animal cells that can be catabolized through Glycogenolysis to yield energy
Proteins are made of
Amino acids
Enzymes are
Proteins that catalyze reactions in all living cells
Essential functions of Proteins (5)
-Catalysis (enzymes)
-Signalling
-Structure of cell
-Transport
-Energy/Gradient Generation
Nonessential amino acids can
Be synthesized by the organism
Essential amino acids
MUST be in the diet, the organism cannot synthesize (make it) on its own
In a dehydration reaction (2)
-H2O is produced
-a peptide bond is formed between the carbon and nitrogen
A polypeptide chain is a
Linear sequence of amino acids connected by a peptide bond
What is the basic structure of an amino acid (3)
-a Carboxyl group (COOH)
-an amino group (NH3)
-a side chain (R group)
Transcription is
DNA making RNA
Translation is
RNA making proteins
What are the two Nucleic Acids
-Deoxyribonucleic Acid (DNA)
-Ribonucleic Acid (RNA)
Nitrogenous Bases of DNA vs RNA
DNA:
-Adenine
-Thymine
-Guanine
-Cytosine
RNA:
-Adenine
-Uracil
-Guanine
-Cytosine
Lipids are ___ and include (3)
-poorly soluble in water
-Fats
-Phospholipids
-Steroids
Three functions of Lipids
-crucial part of cell membranes
-cell signalling
-energy storage
Lipids are often found as ___, which consists of ____
-Triglycerides
-glycerol backbone and 3 fatty acid molecules
A Lipid in a solid state is called ___ while a Lipid in a liquid state is called ___
Fats; Oils
Saturated fats are
Fatty acids that have only single bonds between their C atoms
Unsaturated fats
Have some double bonds in their hydrocarbon chain
Phospholipids (5)
-make up all animal cell membranes
-have 2 fatty acid chains bound to a glycerol backbone
-have a phosphate group bound to the third C
-Hydrophilic head (water soluble)
-Hydrophobic tail (insoluble)
Cholesterol (4)
-made in the liver
-poorly absorbed in the diet
-influences membrane fluidity
-precursor of ALL steroids (including hormones)
Anabolism (3)
-energy stored in cells
-used to help build / repair structures
-small to large molecules
Catabolism (2)
-breakdown of body tissues (ie. large to small molecules)
-used to create energy
The by-product of Metabolism is ___ which is used for (2)
-Heat
-Thermoregulation and Maintaining Homeostasis
Endergonic reactions
Absorb free energy (anabolic)
Exergonic reactions
Release energy (catabolic)
Activation energy is the
Initial energy investment required to reach UNSTABLE transition state
The Transition State is when
Molecules absorb energy and become unstable, thus allowing their bonds to be broken
Enzymes lower ___ by ____
-Activation Energy
-binding to its substrate(s) forming a complex
Two types of enzyme inhibitors are
-competitive (bind reversibly to an enzyme)
-non-competitive (do not bind to the active site)
Feedback inhibition is one of the
Most common way to regulate a metabolic path
Cellular Respiration (3)
-breaks down the molecular components in food
-produces H2O and CO2
-generates ATP
3 stages of Cellular Respiration
- Glycolysis
- Krebs Cycle
- Electron Transport Chain and Oxidative Phosphorylation
Oxidation (2) and an example
-loss of electrons
-losing/sharing electrons to/with oxygen
-glucose is oxidized to form CO2
Reduction (2) and an example
-gaining of electrons
-gaining/sharing electrons from/with Hydrogen
-oxygen is reduced to form water
Glycolysis (4)
-first step in Cellular Respiration
-takes place in cytoplasm
-does NOT require oxygen (anaerobic)
-splitting of glucose into 2 Pyruvic Acids
During cellular respiration, pyruvate is diffused to ____ where ____ occurs
-the mitochondria
-Krebs Cycle and ETC
During the Krebs Cycle ___ is converted to ____
Pyruvate; Acetyl-CoA
Enzyme that catalyses the conversion of pyruvate to Acetyl-CoA
Pyruvate Dehydrogenase
Pyruvate Dehydrogenase (PDH) is controlled by (2)
-Pyruvate Dehydrogenase Kinase (PDK): makes PDH inactive
-Pyruvate Dehydrogenase Phosphatase (PDP): reverses PDK
Main product of the Krebs Cycle used in the Electron Transport Chain is
NADH
One glucose molecule can produce
30-32 ATP
Electron Transport Chain (5)
-occurs in the inner mitochondrial membrane
-consists of four protein complexes labelled I to IV
-electrons (NADH and FADH2) enter through complex I or II
-proton gradient is created within the intermembrane space
-complex IV produces water
The major role of the ETC is (2)
-pump H+ from the matrix into the intermembrane space
-ATP Synthase moves H+ back across the membrane creating ATP
Chemiosmosis is
Using an H+ gradient to do work
What is the effect of strenuous exercise on the ETC (4)
-increase in body temperature -decrease in pH creates an acidosis
-this increase in acid mainly occurs in Complex I, causing less H+ being generated
-cuts ATP synthesis in half, causing fatigue
Traditionally, anaerobic metabolism was thought
That a build up of Lactic Acid was not good and created Hypoxia
The Lactate Shuttle (3):
-in the liver, lactate is converted to glucose via Glyconeogensis
-in glycolysis skeletal muscle, glucose is used to produce lactate which goes to oxidative skeletal muscle
-in oxidative skeletal muscle, lactate is converted back into pyruvate which can either go back to the liver and repeat the cycle OR be used in the Krebs Cycle
