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contains DNA to direct all functions of the cell


contains the genes that direct synthesis of ribosomal RNA

Rough ER

site of protein synthesis

Smooth ER

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

cell membrane

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

Golgi complex

modify and package proteins


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


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


allow internal conditions to change with external conditions


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


genetic makeup


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


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


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?


Carbohydrate symbol


3 main functions of carbohydrates

immediate energy
stored energy
structural molecules


3-7 carbon atoms; aka simple sugars


2 monosaccharides linked together by covalent bond
Ex. sucrose


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

energy metabolism
cell structure

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.


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:
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


long strands of nucleotides:

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


cytosine, uracil, thymine


Adenine, guanine

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?

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


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

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


chemical messenger

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

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

Amino acids

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

Reproductive hormones


important for electrolyte balance; regulate sodium uptake from kidneys

Example of Mineralocorticoids


Example of Glucocorticoids



stress hormone

Reproductive hormones

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"


Stress 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

Gas messengers

freely diffuse across cell membrane, very short lived, turn off or on certain enzymes

Lipid messengers



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

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


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)


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)


what receives message and where; ligand biding domain of receptor

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