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157 terms

Animal Physiology

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Nucleus
contains DNA to direct all functions of the cell
Nucleolus
contains the genes that direct synthesis of ribosomal RNA
Rough ER
site of protein synthesis
Smooth ER
synthesizes fatty acids, steroids, and lipids
Ribosomes
Assemble amino acids into proteins
Microtubles and microfilaments
provide strength and support; enable cell motility; transport
Microvilli
Increase surface area for absorption
cell membrane
acts as a gateway for and barrier to movement of material between the interior of the cell and the extracellular fluid
cytosol
contains dissolved nutrients, ions, wastes, insoluble inclusions; suspends the organelles
centrioles
direct movement of DNA during cell division
lysosomes and peroxisomes
digest bacteria, old organelles; metabolize fatty acids
mitochondria
produces most of the cell's ATP
Golgi complex
modify and package proteins
Hippocrates
first to emphasize careful observation and taking notes, and to start treating various diseases
"Father of Medicine"
Claudius Galenus
first to begin doing controlled experiments to figure out how the body works
"Father of Physiology"
Andreas Vesalius
authored 1st anatomy book
William Harvey
first to understand how blood moves through the body; first to say heart is like a pump
Claude Bernard
said that internal environment was separate and distinct from external environment
Walter Cannon
coined the term homeostasis
homeostasis
balance, regulation
feedback loops
how to maintain homeostasis
controlled variable
the property that is being held constant
set point
the number or range that the control must be kept at
negative feedback loops
counteract the stimulus-very common
positive feedback loops
reinforce the stimulus-not very common
conformers
allow internal conditions to change with external conditions
regulators
maintain relatively constant internal conditions even though external environment is changing
acute changes
very short term changes; reversible; happen right after the external environment changes
chronic changes
long term changes in physiology; still reversible; occur days, weeks, or months after environment changes
evolutionary changes
alteration of gene frequencies over time; looks more at population rather than individual
developmental changes
changes that an animal undergoes that are programmed in and happen as the animal matures
changes controlled by periodic biological clocks
changes due to repeating patterns; daily or monthly changes due to some factor
genotype
genetic makeup
phenotype
morphology, physiology, behavior
phenotype plasticity
the ability of a single genotype to generate more than one phenotype depending on the environmental conditions; possible because an individual possesses the genetic code to adopt multiple phenotypes
polyphenism
the ability of a single genome to produce two or more alternate morphologies within a single population in response to an environmental cue
natural selection
the increase in frequency of genes that produce phenotypes that raise the liklihood that animals will survive and reproduce
adaptation
the product or process of evolution by natural selection
adaptive significance
the reason why a trait is an asset; the reason why natural selection favored the evolution of a trait
genetic drift
random changes in the frequency (number of occurrences within a given time period) of genotypes over time; occurs by chance
Integral proteins
tightly bound to membrane; either embedded in the bilayer or spanning the entire membrane
Peripheral proteins
weaker association with lipid bilayer; typically bind to integral membrane proteins or glycolipids
passive diffusion
movement of molecules from high concentration to low concentration; no specific transporters required; no energy required
facilitated diffusion
uses a concentration gradient; no energy required; requires a protein to carry the molecule across the membrane
active transport
moves against the concentration gradient; requires energy; requires a protein to carry molecule across the membrane
Which types of transport use moving down a concentration gradient?
passive diffusion and facilitated diffusion
Which types of transport use a protein to carry molecules?
facilitated diffusion and active transport
Which types of transport require energy?
active transport
Which types of transport don't require energy?
passive diffusion and facilitated diffusion
membrane potential
voltage difference across all animal cell membranes
Most common carbohydrate in animal diets?
glucose
Carbohydrate symbol
(CH2O)n
3 main functions of carbohydrates
immediate energy
stored energy
structural molecules
monosaccharides
3-7 carbon atoms; aka simple sugars
disaccharides
2 monosaccharides linked together by covalent bond
Ex. sucrose
Polysaccharides
long chains of monosaccharides used more as long term energy storage; aka complex carbs
Examples of polysaccharides
starch and glycogen for energy storage
chitin for structural molecule
Lipids
hydrophobic; carbon backbone
3 main functions of lipids
energy metabolism
cell structure
signaling
Examples of lipids
fatty acids, triglycerides, steroids
Fatty acids
have carbon chain of 3-30 carbons; carboxyl group on end; saturated or unsaturated
Saturated fatty acids
no double bonds; solid at room temp. because they can pack together very closely
Unsaturated fatty acids
at least one double bond between carbon atoms; can't pack together as closely so usually liquid at room temp.
Triglycerides
fatty acids are stored for long term use as triglycerides; 3 fatty acids+ 1 glycerol
Where do vertebrates store triglycerides?
adipose tissue and liver
Where do invertebrates store triglycerides?
hypatopancreas
Functions of proteins
cell structure and function
What are proteins made up of?
polymers of amino acids
Primary protein structure
linear sequence of amino acids (joined together by peptide bonds)
Secondary protein structure
protein starts to fold in on itself:
alpha helix
beta plated sheets
Tertiary protein structure
different regions begin to fold together; needs to be stabilized by different bonds
Quaternary protein structure
not required by all proteins; forms when different proteins/polypeptides come together
2 types of nucleic acids
Deoxyribonucleic acid
Ribonucleic acid
Polymers
long strands of nucleotides:
cytosine
adenine
guanine
thymine
uracil
Parts of nucleotides
phosphate group, sugar group, nitrogenous base
What are nucleotides linked by?
phosphodiester bonds
What is the difference in DNA and RNA?
DNA has thymine where RNA has uracil;
RNA has an extra oxygen
Pyrimidines
cytosine, uracil, thymine
Purines
Adenine, guanine
How many bonds does G-C have?
3 hydrogen bonds
How many bonds does A-T have?
2 hydrogen bonds
Histones
DNA binding protein; compresses and shields DNA
3 pathways to generate ATP
Glycolysis
Citric Acid Cycle
Electron Transport System
What cycle breaks down carbohydrates?
glycolysis
What cycle breaks down proteins?
glycolysis or citric acid cycle
What cycle breaks down lipids?
glycerol: glycolysis
fatty acids: convert to acetyl CoA and enter citric acid cycle
Chemiosmotic theory
movement of electrons through the electron transport system
cell signaling
communication between cells
signaling cell
the cell that sends the signal
target cell
recieves the signal; also has to respond
Direct cell signaling
physical connection between signal cell and target cell; good for cells that are close together
gap junction
cell junction that allows chemical messenger to pass directly from cell to cell
connexins
individual proteins subunits that make up gap junctions in vertebrates
innexins
individual protein subunits that make up gap junctions in invertebrates
How do gap junctions help hydrophilic messengers?
Keep them from dissolving in extracellular fluid by getting them quickly from cell to cell
Indirect cell signaling
no physical connection between signal cell and target cell
Types of indirect cell signaling?
autocrine, paracrine, endocrine, neural
Autocrine cell signaling
one cell basically talking to itself
Paracrine cell signaling
indirect; cell signaling over a short distance
Endocrine signaling
signal cell releases message (aka hormone); hormones enter circulatory system and can go a long way
Neural signaling
signaling cell (very elongated cell) that uses electric charge for signal
Neurotransmitter
chemical messenger
How long does autocrine and paracrine signaling take?
seconds to milliseconds
How long does nervous (neural) signaling take?
milliseconds
How long does endocrine signaling take?
seconds to minutes; slowest
Exocrine signaling
cells have ducts; hormones excreted through some duct normally to outside of body surface
Which type of signal can be made ahead of time and stored? Why?
hydrophilic; because they can't cross the cell membrane (hydrophobic could leave whenever)
How is the hydrophilic signal released?
Through exocytosis from vesicle to membrane wall; enters circulation and dissolves; goes to site of target cell and leaves circulatory system to go to target cell
How is the hydrophobic signal released?
made when needed and freely exit the cell; enters circulatory system and most bind to a carrier protein; goes to site of target cell and unbinds then interacts with target cell
Where does the receptor need to be for hydrophilic signal?
on the plasma membrane
Where does the receptor need to be for hydrophobic signal?
on membrane or inside of cell
Types of peptide messengers
amino acids
peptides
proteins
Amino acids
hydrophilic and hydrophobic; R group determines which
Peptides
hydrophilic; 50 or less amino acids
Proteins
hydrophilic; over 50 amino acids long
Steroid messengers derived from ______.
cholesterol
Types of steroid messengers
Mineralocorticoids
Glucocorticoids
Reproductive hormones
Mineralocorticoids
important for electrolyte balance; regulate sodium uptake from kidneys
Example of Mineralocorticoids
Aldosterone
Example of Glucocorticoids
Cortisol
Glucocorticoids
stress hormone
Reproductive hormones
regulate sex specific characteristics and secondary characteristics and have a place in reproduction
Example of reproductive hormones
Estrogens
Biogenic amine messengers
chemical messengers that have an amine group --NH3
Which biogenic amine messengers are derived from tyrosine?
Catecholamines
Dopamine
Epenephrine
Which biogenic amine messengers are derived from tryptophan?
Melatonin
"Fight or flight response"
Catecholamines
Stress response
dopamine and epenephrine
Melatonin
hormone, neurotransmitter that deals with sleep/wake cycles and cicadian rhythm
Which biogenic amine messengers are derived from histidine?
histamine
Histamine
immune response/allergic response
Which biogenic amine messengers are derived from choline and acetyl CoA?
acetylcholine
Acetylcholine
important at muscular junctions where nervour system and muscular system work together
Gas messengers
freely diffuse across cell membrane, very short lived, turn off or on certain enzymes
Lipid messengers
eicosanoids
Prostoglandins
involved in sensation of pain
Leukotrienes
responsible for parts of inflammatory response
Agonist
ligand mimic; can bind to receptor and also activates cell response from target cell
Antagonist
ligand mimic; can bind to receptor but does not activate a cellular response (block receptor so real messenger can't bind)
Ligand
Any molecule that can bind to a receptor
Receptor isoforms
similar or same receptor among gene families that can bind same ligand but have different response
Receptor affinity
how much they want to bind to ligand
Kd
disassociation constant; concentration of ligand messenger at which half of receptors are bound
High affinity receptor
low Kd (strong attraction to ligand)
Low affinity receptor
high Kd (needs more concentration of message to get half of receptors bound)
Ka
affinity constant
High Ka
high affinity for ligand (really wants to bind to ligand)
Low Ka
has low affinity (takes more ligand to get it bound)
Receiver
what receives message and where; ligand biding domain of receptor
Transducer
receptor acts as this because as soon as it binds it has a shape change and sends signal into cell
amplifier
pathways inside the cell which can work by activating multiple signals down the line
Responder
what responds to the message
Examples of signal transduction pathways
Intracellular pathways
Ligand-gated ion channels
Receptor enzymes
G-coupled receptors
Sensor
detects the level of the regulated variable
Integrating center
evaluates the incoming information and sends a signal to the effector
Effector
the target tissue that can cause and effect or change the regulated variable
Negative feedback
brings regulated bariable back to the predetermined set point; counteracts the stimulus