Biochemistry Basics Flashcards
What is polarity?
Partial charge separation
What makes a water molecule polar?
The more electronegative oxygen atom is partially negative, the side containing the less electronegative hydrogen atoms is slightly positive
How is a water molecule arranged?
Slightly bent
Two hydrogen atoms
One oxygen atom
How much of the human body is water?
At least 55%
How much of human lung tissue is water?
80%
What are the major uses of carbohydrates?
Provide ready source of fuel
Energy storage
Carbohydrates
Make up most of the organic matter on earth and provide the structural backbone for DNA and RNA
What are monosaccharides?
Simple sugars, i.e. glucose and fructose
What are disaccharides?
Double sugars, i.e. sucrose (table sugar) and lactose (milk sugar)
What are polysaccharides?
Long chains of simple sugars that are NOT sweet to taste, i.e. glycogen and starch (excess storage of glucose)
What is passive diffusion?
Molecules move through the cell membrane from higher to lower concentrations
What are the four main ways to describe lipids/fats/oils?
Hydrophobic, hydrophilic, lipophobic, lipophilic
What does it mean for a lipid to be hydrophobic?
It is insoluble in water
What does it mean for a lipid to be hydrophilic?
It is soluble in water
What does it mean for a lipid to be lipophobic?
It is insoluble in oil
What does it mean for a lipid to be lipophilic?
It is soluble in oil/loves fat
Lipids/fats/oils
Contain energy stored in numerous carbon bonds
Triglycerides
A lipid/fat/oil
glycerol bonded to 3 fatty acid chains
Unsaturated fat
Includes omega-3 and omega-6
Phospholipid bilayer membrane
Cell membrane
Made of a double layer of phospholipid molecules
Proteins and cholesterol supply structural stability to membrane
Proteins
Chains of amino acids
Major part of the structure of organisms
20 primary proteins; 9 humans cannot make
What are the 9 proteins humans cannot make?
histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine
What foods are necessary to eat for histidine?
Beef, turkey, lamb, chicken
What foods are necessary to eat for Isoleucine?
egg whites, soy, turkey
What foods are necessary for leucine?
soybeans, lentils, peanuts
What foods are necessary for lysine?
dairy, eggs, sunflower seeds
What foods are necessary for methionine?
tuna, yellow fin, sesame seeds
What foods are necessary for phenylalanine?
pork, salmon, beef, chicken
What foods are necessary for threonine?
beans, lentils, nuts, seeds
What foods are necessary for tryptophan?
turkey, split peas, cashews
What foods are necessary for valine?
eggs, seaweed, watercress, soy
What is phenylketonuria?
aka PKU
Deficiency in phenylalanine hydroxylase
Impaired conversion of phenylalanine to tyrosine
High levels of phenylalanine in blood which causes abnormal CNS development and severe mental retardation by 1 year
How is phenylketonuria treated?
limit phenylalanine consumption
Hemoglobin
oxygen carrier in red blood cells
each subunit contains an oxygen-binding heme
binds also with carbon dioxide and causes irreversible CNS damage to myelin
How does smoking impact oxygen levels in the blood?
Reduces the oxygen-carrying capacity of blood cells
Enzyme
Protein that acts as catalysts in biochemical reaction
Name often ends in “ase”
Acetylcholine transferase
Most efficient enzyme in the body
works for muscle action
Monoamine oxidase
Breaks down monoamines
Liver Enzymes
Critical for metabolism of nutrients
What do increased serum levels of liver enzymes indicate?
Alcoholic hepatitis
Active viral hepatitis (A, B, or C)
Drug-induced heptatitis
Ethyl Alcohol Metabolism
- Ethanol is is broken down by Alcohol Dehydrogenase into Acetaldehyde
- Acetaldehyde is broken down by Aldehyde Dehydrogenase into Acetate
Genetic Differences in ethyl alcohol metabolism
Females have less alcohol dehydrogenase in the digestive system, which means they metabolize alcohol slower
Racial Differences in ethyl alcohol metabolism
50% of Chinese and Japanese have less active aldehyde dehydrogenase
Antabuse
Inactivates acetaldehyde dehydrogenase
Causes nausea because of higher levels of acetic acid
Cytochrome P450
Proteins with a heme group Involved in various intracellular electron transfers Oxidation reactions Located in liver Involved in drug metabolism Leads to drug-drug interactions
DNA
Deoxyribonucleic acid
molecule with nucleotide bases and deoxy-ribose sugar and phosphate groups
Located in cells nucleus and organelles
Basis for inherited features
Gene
Unit of hereditary information coding for a specific phenotypic trait
Human Genome
46 chromosomes
22 pairs autosomal
1 pair sex-linked (XX = female, XY = male)
3 billion base pairs
Cell Structure
Cell membrane, nucleus, cytoplasm, ribosomes, endoplasmic reticulum, mitochondria
Cytoplasm
Water-soluble proteins
Ribosome
Protein synthesis site
Endoplasmic Reticulum
Lipid and steroid synthesis
Mitochondria
ATP synthesis (energy)
Neuron
Cell body/soma, axon, dendrites
Axons
Send messages
Soma/Cell Body
Synthesizing and energizing
Dendrites
Receive messages, excitatory and inhibitory
Neuron communication
Synapse, synaptic gap/cleft, pre-synaptic membrane, post-synaptic membrane, second messenger system
Neurotransmitters
Monoamines: Indolamines–Serotonin
Catecholamines: Dopamine, Epinephrine, Norepinephrine
Acetylcholine
Amino Acids: GABA, Glutamate, Glycine
Neuropeptides
Endorphins
Substance P
Enkephalins
Behavior
Responding to stimuli
What are the three elements of adaption?
- Detection of environmental stimuli
- Our responses
- The ability to coordinate responses with stimuli
Behaviorist Triangle
Stimuli, Response, Coordination of the two
Receptors
Cellular structures that can detect stimuli
Effectors
Cells or groups of cells that specialize in responding to stimuli
Found in muscles, internal organs, and glands
Conductor Cells
Link receptors to effectors
Nervous System
Made up of cellular units called neurons
What is the function of the nervous system?
To conduct electrochemical signals (neural impulses) between receptors and effectors
What is the function of the circulatory system?
To transport energy-rich nutrients and oxygen to all cells of the body
Describe neural action
Fast, brief, discrete
Describe hormonal action
Slow, prolonged, and diffuse
Protoplasm
- intricately organized substances
- proteins, fats, sugars, and inorganic salts
- in the cell in a 95% water solution
What does the cell membrane do?
- Separate protoplasm from the environment
- Is a passive mold
- Regulates flow of materials
Nuclear Membrane
- Second membrane
- Separates the nucleus from the rest of the cell (cytoplasm)
Nucleus
- Comprised of chromosomes
- Functions include cell reproduction and to regulate cytoplasm activities
What all makes up the nucleus?
The nuclear membrane (outside) which has pores in it. Inside is the nucleolus and chromatin
Cytoplasm
Contains organelles such as mitochondria, ribosomes, and endoplasmic reticulum
Mitochondria
Cell powerhouse (respiration)
Ribosomes
Produce proteins with mRNA help
Endoplasmic Reticulum
- tubules that link outer and internal cell
- Passive skeleton
- Transport system
What the functions of a cell?
- Draws energy from the environment and processes it
- Produces neural impulses
- Produces movement
Efferent Cells
Exit, sends information from structure (like from the spine)
Afferent Cells
Brings information into the structure (like to the spine)
Respiration
- The process in which energy is broken down and stored by the organism
- Accomplished by mitochondria
Enzymes
- Energy directors
- Proteins containing amino acids
Blood brain barrier
Mechanism to keep most chemicals out of the brain, as it lacks the immune system present in the rest of the body
Endothelial cells
- Form the walls of the capillaries
- Are tightly joined
Nervous Systems
Central Nervous System (CNS), Peripheral Nervous System (PNS), Autonomic Nervous Systems, Circulatory System
Central Nervous System
Includes the brain and spinal cord
Peripheral Nervous System
Everything else aside from the brain and spinal cord
What are the types of neurons?
Motor, Sensory, and Interneurons
Sensory Neurons
- Afferent (taking information TO the brain)
- Found in the PNS
- Types: bipolar, unipolar, pseudounipolar
Motor Neurons
- Efferent (taking information FROM the brain)
- Found in the PNS
- Multipolar
Interneurons
- Found in the CNS
- Types: projection neurons and local-circuit neurons
Projection neurons
Golgi Type 1: Purkinje, pyramidal
Local-Circuit Neurons
Golgi Type II: Stellate Cell
Neuroglial or Glial Cells
- CNS: Macroglia and microglia
- PNS: neurilimma cells
Macroglia
Includes oligodendrocytes and astrocytes
Microglia
Includes phagocytosis
Neurilimma cells
- Glial cells found in the PNS
- Includes Schwann Cells and Satellite Cells
What are the three types of synapses?
Axodendritic, Axosomatic, Axoaxonic
Axodendritic synapse
The synapse between the axon terminal branch and dendrites
Axosomatic synapse
The synapse between the axon terminal branch and a soma (cell body)
Axoaxonic synapse
The synapse between the axon terminal branch and another axon terminal branch
