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contains DNA to direct all functions of the cell
contains the genes that direct synthesis of ribosomal RNA
site of protein synthesis
synthesizes fatty acids, steroids, and lipids
Assemble amino acids into proteins
Microtubles and microfilaments
provide strength and support; enable cell motility; transport
Increase surface area for absorption
acts as a gateway for and barrier to movement of material between the interior of the cell and the extracellular fluid
contains dissolved nutrients, ions, wastes, insoluble inclusions; suspends the organelles
direct movement of DNA during cell division
lysosomes and peroxisomes
digest bacteria, old organelles; metabolize fatty acids
produces most of the cell's ATP
modify and package proteins
first to emphasize careful observation and taking notes, and to start treating various diseases
"Father of Medicine"
first to begin doing controlled experiments to figure out how the body works
"Father of Physiology"
authored 1st anatomy book
first to understand how blood moves through the body; first to say heart is like a pump
said that internal environment was separate and distinct from external environment
coined the term homeostasis
how to maintain homeostasis
the property that is being held constant
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
allow internal conditions to change with external conditions
maintain relatively constant internal conditions even though external environment is changing
very short term changes; reversible; happen right after the external environment changes
long term changes in physiology; still reversible; occur days, weeks, or months after environment changes
alteration of gene frequencies over time; looks more at population rather than individual
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
morphology, physiology, behavior
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
the ability of a single genome to produce two or more alternate morphologies within a single population in response to an environmental cue
the increase in frequency of genes that produce phenotypes that raise the liklihood that animals will survive and reproduce
the product or process of evolution by natural selection
the reason why a trait is an asset; the reason why natural selection favored the evolution of a trait
random changes in the frequency (number of occurrences within a given time period) of genotypes over time; occurs by chance
tightly bound to membrane; either embedded in the bilayer or spanning the entire membrane
weaker association with lipid bilayer; typically bind to integral membrane proteins or glycolipids
movement of molecules from high concentration to low concentration; no specific transporters required; no energy required
uses a concentration gradient; no energy required; requires a protein to carry the molecule across the membrane
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?
Which types of transport don't require energy?
passive diffusion and facilitated diffusion
voltage difference across all animal cell membranes
Most common carbohydrate in animal diets?
3 main functions of carbohydrates
3-7 carbon atoms; aka simple sugars
2 monosaccharides linked together by covalent bond
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
hydrophobic; carbon backbone
3 main functions of lipids
Examples of lipids
fatty acids, triglycerides, steroids
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.
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?
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:
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
long strands of nucleotides:
Parts of nucleotides
phosphate group, sugar group, nitrogenous base
What are nucleotides linked by?
What is the difference in DNA and RNA?
DNA has thymine where RNA has uracil;
RNA has an extra oxygen
cytosine, uracil, thymine
How many bonds does G-C have?
3 hydrogen bonds
How many bonds does A-T have?
2 hydrogen bonds
DNA binding protein; compresses and shields DNA
3 pathways to generate ATP
Citric Acid Cycle
Electron Transport System
What cycle breaks down carbohydrates?
What cycle breaks down proteins?
glycolysis or citric acid cycle
What cycle breaks down lipids?
fatty acids: convert to acetyl CoA and enter citric acid cycle
movement of electrons through the electron transport system
communication between cells
the cell that sends the signal
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
cell junction that allows chemical messenger to pass directly from cell to cell
individual proteins subunits that make up gap junctions in vertebrates
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
signal cell releases message (aka hormone); hormones enter circulatory system and can go a long way
signaling cell (very elongated cell) that uses electric charge for signal
How long does autocrine and paracrine signaling take?
seconds to milliseconds
How long does nervous (neural) signaling take?
How long does endocrine signaling take?
seconds to minutes; slowest
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
hydrophilic and hydrophobic; R group determines which
hydrophilic; 50 or less amino acids
hydrophilic; over 50 amino acids long
Steroid messengers derived from ______.
Types of steroid messengers
important for electrolyte balance; regulate sodium uptake from kidneys
Example of Mineralocorticoids
Example of Glucocorticoids
regulate sex specific characteristics and secondary characteristics and have a place in reproduction
Example of reproductive hormones
Biogenic amine messengers
chemical messengers that have an amine group --NH3
Which biogenic amine messengers are derived from tyrosine?
Which biogenic amine messengers are derived from tryptophan?
"Fight or flight response"
dopamine and epenephrine
hormone, neurotransmitter that deals with sleep/wake cycles and cicadian rhythm
Which biogenic amine messengers are derived from histidine?
immune response/allergic response
Which biogenic amine messengers are derived from choline and acetyl CoA?
important at muscular junctions where nervour system and muscular system work together
freely diffuse across cell membrane, very short lived, turn off or on certain enzymes
involved in sensation of pain
responsible for parts of inflammatory response
ligand mimic; can bind to receptor and also activates cell response from target cell
ligand mimic; can bind to receptor but does not activate a cellular response (block receptor so real messenger can't bind)
Any molecule that can bind to a receptor
similar or same receptor among gene families that can bind same ligand but have different response
how much they want to bind to ligand
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)
high affinity for ligand (really wants to bind to ligand)
has low affinity (takes more ligand to get it bound)
what receives message and where; ligand biding domain of receptor
receptor acts as this because as soon as it binds it has a shape change and sends signal into cell
pathways inside the cell which can work by activating multiple signals down the line
what responds to the message
Examples of signal transduction pathways
Ligand-gated ion channels
detects the level of the regulated variable
evaluates the incoming information and sends a signal to the effector
the target tissue that can cause and effect or change the regulated variable
brings regulated bariable back to the predetermined set point; counteracts the stimulus