Final Comprehensive Flashcards
how are organisms organized from cell to organ system
chemical level-cellular level-tissue level-organ level-organ system
what characteristics are needed for maintaining life
a. movement
b. responsiveness
c. growth
d. reproduction
e. respiration
f. digestion
g. metabolism
h. excretion
what is homeostasis(Fig.1.4)
“unchanging”
- describes body’s ability to maintain internal conditions even if external is changing
ex. body temp, blood pressure, heart activities - homeostasis is maintained via communication through electrical impulses through the nervous system or blood borne hormones in the blood(endocrine)
positive feedback loop
the result or response enhances the original stimulus so that the response is accelerated
- positive because the change that results proceeds in the same direction as initial change, causing the variable to deviate further and further from its original value or range
ex. blood clotting, increasing contractions
negative feedback loop
The output shuts off the original effect of the stimulus or reduces intensity.
this mechanism causes the variable to change in a direction opposite to that of the initial change, returning it to its ideal value
ex. regulation of body temperature
isomer
each of two or more compounds with the same formula but a different arrangement of atoms in the molecule and different properties.
synthesis combination reaction
molecules combine to form larger more complex molecules
-involves bond formation
A+B=AB anabolic activities
decomposition
bonds are broken in larger molecules resulting in smaller, less complex molecules
AB= A+B , catabolic activites
ex glycogen is broken down to release glucose units
exchange or displacement
involve both synthesis and decomposition - bonds are both made and broken
ex. ATP transfers terminal phosphate group to glucose to from glucose-phosphate-breaking and bond and forming another
what factors affect rate of chemical reactions and how
- temperature-increase temp , higher kinetic energy, faster reaction
- concentration- more particles, more reactions
- particle size- the smaller the particles, faster the reaction
- catalysts-substances that increase the rate of chemical reactions without them being altered or part of the product
Acid
are electrolytes, they will break up in water and conduct electricity,
- sour taste
- dissolve many metals
- dissolve in water and release hydrogen ions(protons) and anions
salt
ionic compound that have cations other than H+ and anions other than hydroxyl ion
Ex. NaCl, build teeth.conduct nerve signals, calcium phosphate
base
- electrolyte that take up H+
- bitter, slippery
- proton acceptors-take H+ ions in detectible amounts
- dissolve in water and release hydroxyl ions (-OH & cation)
how do buffers work?
substances that are going to minimize change in pH , they do this by accepting H+ when too many, and donates H+ when it is too few - they can act like an acid or a base
what properties does water have that makes it vital to life
a. high heat capacity
b. high heat of vaporization
c. polar solvent
d. reactivity
e. cushioning
carbohydrates
CARBS- cellular fuel as sugars, storage as starches
- monosaccharides, ex. glucose
- disaccharides, ex. sucrose, lactose
- polyasaccharides, ex. starch, cellulose, glycogen
lipids
LIPIDS-energy storage, protection, hormones (steroids)
- triglycerides-fats or oils; saturated or unsaturated
- phospholipids- cell membrane
- steroids- ex. cholesterol in membranes, sex hormones
proteins
PROTEINS- structure and function (hormones, enzymes, antibodies
- fibrous vs. globular(functional)
- structure: primary, secondary, tertiary, quarternary
how do enzymes work
- help speed up reactions that normally take very slowly-catalysts
- can consist entirely of protein or protein and & a cofactor(coenzyme) -metal or organic molcule
- lowers the activition anergy needed to start a reaction
what causes proteins to denature
- proteins unfold-sensitive to environment, pH drops, temperature rises, loose 3D shape,
- H bonds in proteins can be broken by extremes in temp or pH, causing the protein to unfold
Nucleic Acids
make up DNA and RNA; genetic material or cell
DNA base pairs: Adenine+Thymine, Guanine +Cytosine
RNA base pairs: Adenine+Uracil, Guanine + Cytosine
protein primary structure
linear sequence of amino acids
protein secondary structure
alpha helix or beta pleated sheets
protein tertiary structure
alpha helices beta sheets fold on one another in compact like ball-globular
protein quarternay structure
2 or more tertiary structures together
fibrous proteins
- long, strand-like, water insoluble
ex. collagen & keratin-structure proteins found in skin
globular proteins
- compact, sherical, water soluble, used for functional purposes
ex. antibodies, hormones, shape pf protein determines function
mitochondria
power plants of the cell, job is to harvest chemical energy from food, use this energy to create ATP, higher activity more mitochondria
ribosomes
made up of proteins and RNAs, site of protein synthesis
- can be free floating in cytoplasm
- can be attached to Rough ER
Rough Endoplasmic Reticulum
contains ribosomes that manufacture proteins secreted from cells
-makes components of membranes
Smooth Endoplasmic Reticulum
SMOOTH ER- contains enzymes on catalysing many reactions- NO role in protein synthesis
- lipid metabolism, cholesterol synthesis
- synthesis of steroid-based hormones-like sex hormones
- absorb, synthesize & transport fats
- detox certain drugs, pesticides and carcinogens
- breakdown the stored glycogen to form free glucose(in liver cells especially)
Golgi apparatus
GOLGI APPARATUS- Traffic director for cellular proteins
- consists of stacked and flattened membraneous sacs, shaped like hollowed dinner plates
- the GA receives transport vesicles from the Rough ER, modifies them(ex. + phosphate group), sorts them and sends them out the other side
Lysosome
LYSOSOMES- contains digestive enzymes, it is their job to break things down
Cytoskeleton
CYTOSKELETON- cell skeleton; network of rods running through the cytosol providing support and machinery to generate cell movements
-contains microtubule, intermediate filaments and microfilaments
cellular extension- flagella
long projections formed by centrioles; propel an entire cell
ex. sperm
cellular extension-cilia
- whiplike motile cellular extensions occuring in great numbers on some cell surfaces
ex. respiratory tract, pseudostratified columnar
cellular extension- microvilli
- tiny finger-like extensions of plasma membrane projecting from a free cell surface
ex. intestine, kidney, higher surface area for more absorption
nucleus
control center of the cells, contains genetic info
-made up of nuclear membrane, nucleoli & chromatin
Passive transport
- simple diffusion
- facilitated diffusion-(carrier mediated and channel mediated)
- osmosis
simple diffusion
nonpolar and lipid soluble substances diffuse directly through the lipid layer
diffusion
where molecules or ions move from an area of higher concentration to an area of lower concentration-down their concentration gradient
facilitated diffusion(carriers& channels)
- glucose, amino acids & ions, go straight across or with help of carrier protein, passive transport
- CARRIERS are proteins that transport large or polar molecules
- CHANNELS are aqueous filled proteins that allow ions or water to pass through (leaky, chemically or electrically gated)
osmosis
diffusion of a solvent, often water, through a selectively permeable membrane, something liquidy, particles can’t go through
-water uses Aquaporins- water tends to move from areas of higher water lower solute to areas of lower water & higher solute, until equilibrium occurs
tonicity
ability of cell to change its shape by altering internal water volume
isotonic
concentration is the same inside and outside of cell-normal- no net movement
hypertonic
-move solutes outside, water will leave the cell-cell shrivels shrinks -CRENATE
hypotonic
-more solutes in the inside than outside, water will move into the cell; cell will eventually burst-LYSIS
Active transport
-diffusion requires carrier proteins that combine specifically reversibly with transported substances
- requires energy because it is pumping molecules against their concentration gradient
Ex. Ca 2+, Na+, K+
Primary active transport
- Ca2+, H+, main one is Na+/K+ pump
- K+ /Na+ pump maintains the higher gradient of K+ inside the cell and Na+ outside the cell- for nerve and muscle cells to function and for fluid balance in normal cells
vesicular transport
fluids containing large particles and macromolecules are transported across cellular membranes inside membraneous sacs called “vesicles”
Exocytosis
transport out of cell
endocytosis
transport into cell
transcytosis
movement into, across, then out of cell
substance(vesicular) trafficking
transport from one area of the cell to another
3 types of endocytosis
- phagocytosis
- pinocytosis
- receptor-mediated endocytosis(& transcytosis)
phagocytosis
cellular eating
ex. WBC engulfs bacteria
pinocytosis
cellular drinking, allows sampling of of extracellular fluid
ex. cells in intestine use this to absorb nutrients
receptor-mediated endocytosis & transcytosis
very selective receptors in membrane bind only to certain substances
ex. hormones, enzymes
- flu, diptheria, and Cholera also take this route
the resting membrane potential is determined by…
the concentration of K+ potassium ions and by the differential permeability of the membrane to ions
-to maintain proper K+/Na+ balance, active transport of these molecules occurs
membrane potential
voltage across the membrane -its electrical potential energy from the separation of oppositely charged particles
three layers of skin
epidermis, dermis, hypodermis
epidermis
-outer layer
keratinized(hard), stratified squamous epithelium made of four distinct cell types and 4-5 layers
dermis
- under epidermis
- strong, flexible connective tissue, supplied with nerves, blood vessels and lymphatic vessels
hypodermis
- (superficial fascia)- mostly made of adipose(fat) tissue
- functions: fat storage, insulation, shock absorption, anchors your skin to muscle underneath