exam 4 Flashcards
locomotion
movement of an organism under its own
power
The cost of locomotion for running, flying, and
swimming animals decreases
with body mass
Vertebrate skeletal and cardiac muscle tissue is made of long, slender cells called
muscle fibers
Each muscle fiber has many threadlike, contractile structures called
myofibrils
myofibrils are striated due to alternating light-dark units
called
sarcomeres
sarcomeres shorten=
myofibrils contract
sarcomeres lengthen =
myofibrils relax
Muscle cells contain many ____, which contain
many sarcomeres
myofibrils
Sarcomere made up of two types of proteins: what are they and what do they do
- Actin: composes thin filaments
- Myosin: composes thick filaments
Thin actin filaments are composed of 2 coiled chains of actin:
One end is anchored to the Z disk, which forms the wall
between sarcomeres
* The other end is free to interact with thick filaments
z disk in thin actin filaments
forms the wall
between sarcomeres
contraction of sarcomere
The filaments slide past one another
- The sarcomere shortens with no change
in lengths of the thin and
thick filaments themselves
myosin’s “Head” binds ___ and actin
ATP
myosin head can bind to actin
head which
catalyzes hydrolysis of ATP
ATP binding releases
actin and myosin
rigor mortis
myosin and actin
locked together after an animal dies.
ATP required for myosin to release
actin.
step 1 of myosin and actin interaction
ATP binds to myosin head, causing conformation change, releasing head from actin.
step 2 of myosin and actin interaction
When ATP is hydrolyzed, myosin head pivots and binds to new actin subunit farther down thin filament
step 3 of myosin and actin interaction
When inorganic phosphate is released, head pivots back to original conformation. Power stroke moves entire thin filament relative to thick filament
step 4 of myosin and actin interaction
ADP is released, and myosin head is ready to bind to
another ATP
Thin filaments also contain proteins what are they and what do they regulate
troponin and tropomyosin. regulate muscle activity
also work together to block myosin binding
sites on actin
the 4 steps of myosin and actin interaction is called what
sliding filament model
classes of muscles
Multivariate vs. Univariate:
Multivariate = multiple nucleus
Univariate = single nucleus
classes of muscles
Striated versus unstriated
Striated = striped appreance (e.g., skeletal muscles)
Unstriated = smooth appreance (e.g., smooth)
smooth muscles characteristics
- tapered. thin sheets.
- Lack sarcomeres that are found in skeletal and
cardiac muscle, unstriated. UNIVARIATE. - Essential to function of lungs, blood vessels,
digestive system, urinary bladder, and
reproductive system
cardiac muscle characteristics
- make up walls of heart and responsible for pumping blood. have sarcomeres, striated, branched, connected end to end by intercalated discs.
- generate their own electricity
3.involuntary, spontaneous depolarization- do not require nerves
skeletal muscles
- unbranched, long, multiple nuclei, striped, packed with myofibrils, striated appearance
- attached to bones
- openings of the digestive system and urinary tracts.
damage to skeletal muscles will result in
paralysis
where is a plant getting its mass from
mostly CO2 since its transformed into sugar in photosynthesis
essential nutrient
element or compound required for normal growth and reproduction
Three elements make up 96% of the dry mass of the plant:
carbon
hydrogen
oxygen
macronutrients
plants need large quantities of macronutrients, certain elements, from the soil.
-Some are major components of nucleic acids, proteins, and
phospholipids (e.g., nitrogen, phosphorous, and potassium
micronutrients
plants require micronutrients in small
quantities
usually act as COFACTORS of specific enzymes
zone of maturation contains what
root hairs
how do root hairs absorb nutrients from the soil
electrochemical gradients created by proton pumps
what do root hairs do
provide tremendous surface area for nutrient absorption
how do cations enter root hairs
via channels
how do anions enter root hairs
cotransporters
Fungi and plant roots that live in symbiotic association are called
mycorrhizae
symbiotic relationship between plant and fungi is
mutualistic
fungi- obtain sugar from the plant
plant- receive nutrients from fungi- nitrogen
passive exclusion
root cells lack transporters to bring in toxic ions
active exclusion
plants have mechanisms for coping with toxins that enter their cells
plants exclude toxic ions by
passive and active exclusion
casparian strip blocks negative ions in what
passive exclusion
Metallothioneins and phytochelatins in active exclusion
synthesized by special enzymes
bind to metal ions and prevent them from acting as poison, macromolecules
epiphytic
plants appear to live inthe air
parasites
live on or inside a host in hopes to obtain water or nutrients from host and reduce their fitness
haustoria in heterotroph parasitic plants
penetrate host vascular system to obtain water and nutrients
most parasitic plants are ___ and use haustoria to extract ___ and ions from xylem of host plant
photosynthetic, water
epiphytes characteristic
non parasitic, grow in absence of soil, nutrietns absorbed through the leaves
carnivourous plants
trap insects and other animals. kill their prey and absorb their nutrients. make their own carbs from photosynthesis.
ex. venus fly trap- nitrogen from insect
The force output of skeletal muscle depends on:
) relative proportion of different fiber types
(2) organization of fibers within the muscle
(3) how the muscle is used
The length change of muscle is determined by
length of muscle
fibers or (2) how many sarcomeres
are lined up in a row in each fiber
the force of muscle is proportional
to
cross-sectional area of muscle
cell and (2) number of sarcomeres
lined upside by side, pulling in
synchrony
- Skeletal systems have four functions
Protection from physical and biological assaults
(2) Maintenance of body posture
(3) Re-extension of shortened muscles
(4) Transfer of muscle forces to other parts of body
All animals have one or more of three types of skeletal
systems:
hydrostatic, endoskeletons, exoskeletons
hydrostatic skeletons
use hydrostatic pressure of
enclosed body fluids or soft tissues to support body
endoskeleton vs exoskeleton
have rigid structures inside body
exo- outside
Hydrostatic skeletons: structure
Soft-bodied animals, body wall surrounds a fluid under compression, interior of animal has seawater, coelomic fluid, blood, or soft organs.
Antagonistic muscle groups
cause shape changes in
Hydrostatic Skeletons
-circumferential and longitudinal muscles
Alternating contractions of longitudinal and circumferential
muscles pass down earthworm in waves called
peristalsis
examples of endoskeleton
-Sponge endoskeletons
are made of silica to
provide structural
support
-Echinoderm
endoskeletons are
made of calcium
carbonate to provide
structural support.
endoskeleton structure composed of what
calcium carbonate
It is made of rigid levers
separated by joints—
vertebrates change their
shape largely by changing
joint angles rather than
body segments
vertebrate skeletons were composed of 3 main elements
bones, cartilage, ligaments
bones
have cells in a hard extracellular matrix:
* Bones interact at articulations or joints
cartilage
has cells scattered in a gelatinous matrix of
polysaccharides and protein fibers
ligaments
bands of fibrous connective tissue that binds bones to other bones
Bones attach to skeletal muscle via bands of fibrous connective
tissue called
tendons
Vertebrate skeletons move by changes in joint angles controlled by
antagonistic muscle groups:
flexors and extensors
flexors
pull bones closer together, decreasing joint angles (e.g.,
hamstring
extensors
increase the angle of a joint, straightening it out (e.g.,
quadriceps)
Endoskeletons move by contraction and relaxation
of
flexor and extensor muscles
endoskeleton function
calcium homeostasis
bones store calcium and other minerals
osteoblasts
bone-building cells that secrete protein and
calcium-rich extracellular matrix
osteoclasts
bone-resorbing cells that secrete acid onto bone
tissue when blood calcium levels are low to cause small amounts
of mineral to be resorbed into the blood
osteoporosis
disease in which reduced bone mass can make
bones brittle and susceptible to fracture
exoskeleton structure
exterior skeleton that encloses and protects an
animal’s body
insect exoskeleton
consists of
cuticle made up of proteins and chitin
Crustacean exoskeleton consists
of
cuticle mineralized with calcium carbonate
exoskeleton function
muscles packed within skeleton, must be shed for internal parts to grow, extensor muscles operate jointed skeletons
apodemes in exoskeleton
ingrowths where muscles are attached
How is musculoskeletal structure
adapted for locomotion (biomechanics)
High-speed video and digital images provide insights into
locomotion
type 1 diabetes is treated with ___ injections and ___ to diet
insulin, attention
insulin is produced where
the pancreas
type 2 diabetes is managed how
prescribed diets and exercise
monitoring blood glucose levels
drugs that increase cellular responsiveness to insulin
the incidence of type 2 diabetes is correlated with ___ determined by BMI
obesity
what is an ulcer
eroded area in epithelium that exposes underlying tissues to damage
what is the 5 steps of gas exchange
ventilation, diffusion, circulation, diffusion at the tissues, cellular respiration
step 1. ventilation
movement of air or water through
specialized gas-exchange organ, such as a lung or gill
step 2. diffusion
at respiratory surface where O2from the
air/water move into blood and CO2 from blood into air/water
step 3. circulation
transport of dissolved CO2 and O2
throughout body via circulatory system.
Step 4: Diffusion at the tissues
where O2 from the blood moves into
tissues and CO2 from the tissues move into blood
Step 5: Cellular Respiration:
cells take in O2 and produce CO2
Ventilation and diffusion at the respiratory surface are
accomplished by the ___ system
respiratory
gills of fishes, lungs of tetrapods, and tracheae of insects
___ system is responsible for moving O2, CO2 and other
materials around the body:
circulatory
muscular heart that propels special liquid transport tissue
through body
what is partial pressure
pressure of a particular gas in a mixture of gases
when solving for partial pressure, what is the constant and why
0.21 because oxygen makes up 21 percent of the atmoshpere
ficks law of diffusion states that the rate of diffusion of a gas depends upon five parameters
(1) Solubility of gas
(2) Temperature
(3) Surface area available for diffusion
(4) Differences in partial pressures of gas across the gas-exchange
surface
(5) Thickness of barrier in diffusion
trachea carries inhaled air to narrow tubes called
bronchi
bronchi branch off into even narrower tubes called
bronchioles
lungs are organs for
gas exchange
lungs are divided into tiny sacs called ___ greatly ___ the surface area for gas exchange
alveoli, increase
surface of alveoli consists of
thin aqueous film
* A layer of epithelial cells
* Extracellular matrix (ECM)
material
* Wall of a capillary
negative pressure ventilation is used by humans and other mammals for
pumping air
negative pressure ventilation has 2 steps
inhalation and exhalation
inhalation
diaphragm moves down and pressure in chest cavity is lowered, causing lungs to expand and air to move in
exhalation
as diaphragm relaxes, chest cavity decreases and air is exhaled.
platelets
cell fragments that minimize blood loss
white blood cells
part of immune system
red blood cells
transport oxygen from lungs to body tissues and participate in transporting carbon dioxide from tissues to lungs
Blood is composed of an extracellular matrix called plasma and
has several cellular components
platelets, white blood cells, red blood cells
Hemoglobin is a ___: consists of ___ polypeptide chains, each of which binds to a nonprotein group called a ___
tetramer, four, heme
Each hemoglobin molecule can thus bind up to ___ oxygen
molecules
four
Hemoglobin in
RBCs ….
transports
oxygen to tissues
where are N2 fixing bacteria present
inside plant root cells
infected root cells of legumes form nodules where N2- fixing __ are found
rhizobia (bacteria)
nodules are pink because they contain
leghemoglobin
leghemoglobin protects ____ which is poisoned by ___, by maintaining low levels of free oxygen
nitrogenase, oxygen
step 1 of nitrogen fixing bacteria
young roots release compounds called flavonoids to attract rhizobia
step 2 of nitrogen fixing bacteria
rhizobia contract the flavonoids, they produce nod factors
step 3 of N2 fixing bacteria
nod factors bind to signaling protein on membrane surface of root hairs
when nod factors bind to root hair surface, they set off a chain of events that leads to dramatic ____ changes in the host ___
morphological, legume
essential nutrients cannot be synthesized and must be obtained from diet
amnio acids, fatty acids, vitamins, minerals
complete digestive tracts have 2 advantages
- different chemical and physical processes can be confined to different compartments
- one way flow of food and wastes, material can be ingested and digested without interruption
vital organs and glands are connected to the digestive tract as
accessory structures- contribute digestive enzymes
mechanical digestion
involves chewing and smooth muscle contraction in stomach and small intestines
chemical digestion
occur as food moves through each compartment in digestive tract
in the mouth, enzymes in saliva begin chemical breakdown of
carbohydrates and lipids
chemical digestion of __ begins in the acidic environment of the stomach
protein
chemical processing is completed in
small intestine
salivary amylase
cleaves bonds in starch to release dextrins and disaccharides
salivary glands in the mouth secrete ___ and a slimy substance, ___
amylase, mucus
cells in the tongue synthesize and secrete - which begins the digestion of lipids
lingual lipase
the food propelled down the esophagus by a wave of muscle contraction is called
peristalsis
peristalsis is a ___ that is stimulated by the act of swallowing
reflex
The stomach is a tough, muscular
pouch bracketed on both ends by
ringlike muscles called ____,
which control the passage of
material
sphincters
When food enters the stomach,
muscular contractions result in
churning that mixes and breaks
down the food
mechanically
the other main function of the stomach is __ ___ digestion of protein and lipids
partial chemical
protein digestion- cells in the stomach lining secrete
mucus, pepsinogen, and hydrochloric acid
mucous cells
secrete mucous which lines the gastric epithelium and protects the stomach from damage by HCl
chief cells- have protein- digesting enzyme known as
pepsin
to prevent destruction of chief cells where pepsin is synthesized, it is stored in its inactive form
pepsinogen
parietal cells
present in pits of stomach lining and produce HCl in gastric juice
Parietal cells have a high concentration of
mitochondria and the enzyme
carbonic anhydrase
gastrin hormone in the stomach signals parietal cells to begin secreting
HCl
pancreas- ___ are enzymes that are released from the pancreas into the small intestine and digest ____ to amino acids
proteases, polypeptides
proteases are released as inactive form, transferred through the ____ duct to the small intestine, and activated there by another enzyme known as
pancreatic, enteropeptidase
hormone, ____, stimulates secretion of digestive enzymes from ___ and molecules from gall bladder that aid in processing ___
cholecytokinin, pancreas, lipids
hormone ___ is produced in small intestine in response to the arrival of food from the stomach
secretin
secretin induces flow of ___ ___ from pancreas to small intestine
bicarbonate ions
choleocystokinin stimulates secretion of ___ ____ from pancreas and molecules from gall bladder that aid in processing lipids
digestive enzymes
The small intestine has large surface area for absorption of nutrients and water due to epithelial tissue covered with projections called ____, which have projections called ____
villi, microvilli
Each villus contains ____ ____, and a lymphatic vessel called ___, nutrients pass quickly from epithelial cells
into the body’s transport systems
blood vessels, lacteal
nucleases
digest RNA and DNA
pancreatic amylase
continue digestion of carbohydrates
pancreas also produces enzymes for the digestion of DNA, RNA, and carbohydrates, which are
nucleases, pancreatic amylases
two general principals apply for absorption:
highly selective, happens by active transport
3 step model of glucose uptake
(1) Na+-K+ ATPase in the
basolateral membrane generate
electrochemical gradient.
(2) Glucose and Na+ enters the
cells via a co-transporter in the
apical membrane.
(3) Glucose diffuses into nearby
blood vessels through a glucose
carrier in the basolateral
membrane.
pancreatic lipase
completes digestion lipids, results in release of fatty acids and monoglycerides
fats tend to enter the small intestine in large globules- broken up by ___ before pancreatic ___ can act on them
emulsification, lipase
emulsification results from the action of small molecules called ___ ___ - synthesized in the ___ and secreted in bile, which is stored in the ___
bile salts, liver, gall bladder
monoglycerides and fatty acids enter the small intestine epithelial cells by ___ ____
simple diffusion
inside the cells, fatty acids are processed into protein coated globules called
chylomicrons
When solutes from digested material are absorbed into the
epithelium of the small intestine, water follows
passively by osmosis
water absorption is an important mechanism for
-absorbing water that has been ingested
-reclaiming liquid that was secreted into the digestive tract in saliva, mucus, and pancreatic fluid
the large intestine
absorption and elimination
people with ___ ___ experience abnormally high levels of glucose in their blood because cells cannot import the glucose
diabetes mellitus
type 2 diabetes
resistant to insulin, receptors no longer function correctly
type 1 diabetes
autoimmune disease, do not synthesize sufficient insulin- treated with insulin injections
what is insulin
produced in the pancreas when blood glucose levels are high
insulin binds to receptors on cells and causes them to ___ their rate of glucose uptake and processing
increase
insulin stimulates cells in the liver and skeletal muscle to import glucose from blood and synthesize glycogen from glucose monomers, as a result..
blood glucose levels decline
if blood glucose levels fall too low, cells in the pancreas secrete a hormone called
glucagon
in response to glucagon, cells in the liver catabolize glycogen and produce glucose via __ as a result..
gluconeogenesis (synthesis of glucose from noncarbohydrate compounds)
glucose levels in the blood rise
insulin and glucagon form a
negative feedback system
type 2 diabetes is managed through and correlated with what
-prescribed diets and exercise
-monitoring blood glucose levels
obesity
ulcers are associated with infections from a bacterium called
helicobacter pylori
oxygen -hemoglobin curve or oxygen dissociation curve shows
co-operative binding
co-operative binding makes hemoglobin very __ to changes in the oxygen concentration
sensitive
in response to relatively small change in __ there is a relatively __- change in percentage saturation of hemoglobin
tissue, large
___ ___in red blood cells catalyzes formation of carbonic acid from carbon dioxide i water
carbonic anhydrase
CO2 produced by cellular respiration enters ___ and red blood cells
plasma
circulation- circulatory system carries transport tissues called ___ into close contact with every cell in the body
blood
blood vessels are classified as
arteries, capillaries, or veins
arteries charac
tough, thick walled vessels with elastic fibers that take blood AWAY from the heart under high pressure
small arteries are called
arterioles (smooth muscle fibers)
capillaries
vessels whose walls are just one cell thick and allow GAS EXCHNAGE between blood and tissues in networks called capillary bed
veins
thin walled vessels, larger diameter that RETURN blood to the heart
lymphatic system
mechanism to drain excess fluid
atrium (atria)
receives blood returning from circulation
ventricle
generates force to propel blood out of the heart and through the circulatory system
atria are separated from ventricles by ___valves. if these valves are damaged, it can lead to a heart ___
atrioventricular, murmur
pulmonary artery carries blood to lungs, and pulmonary ___ return freshly oxygenated ___ to heart
veins, blood
circulation is split into 2 circuits
pulmonary and systemic
pulmonary circuit
circuit that takes blood to the lungs and gills
systemic circuit
takes blood to the body
human circulatory system returns blood that is low in oxygen from the body to the ___ ___of heart through 2 large veins called ___ and ___ venae cavae
right atrium, inferior, superior
when right atrium contracts, deoxygenated blood is sent to right ____, which then contracts, sending blood to lungs via ___ ___
ventricle, pulmonary artery
after blood has circulated through capillary beds in the lungs alveoli and becomes ___, it returns to heart through ___ veins
oxygenated, pulmonary
left ventricular walls are so ___ with muscle that when it contracts, it sends oxygenated blood at high pressure through the aorta and into the ___ and capillaries of the ___ circulation
thick, arteries, systemic
cells that initiate contraction in vertebrate heart are known as ___ ____- located in region of right atrium called ____ ___
pacemaker cells, sinoatrial node (SA)
signal in SA node is rapidly conducted throughout left and right atria through ___ and electrical connections between cardiac ___ cells: signal is transmitted through ____ discs
physical, muscle, intercalated
cardiovascular disease
group of aliments collectively affecting the heart and blood vessels
as people age, their blood vessels harden and lose elasticity, a condition called
arteriosclerosis
if arteries that deliver blood to the heart become completely blocked, a myocardial ___ or ___ ___ can occur
infarction, heart attack
specialized pressure-sensing receptors called ____ are found in the walls of the heart and major ___
baroreceptors, arteries
