Bio 311D Exam 3 flashcards

Hormones

signaling molecules

- slow, long-lasting

- all locations

- affect the entire body, growth, development, digestion, reproduction, etc.

Neurons

nerve cells, transmit signal

- very fast

- specific locations

- immediate response, reflexes

signal transduction

hormone bind to receptor

Endocrine Signaling

hormones reach targets via bloodstream

- maintain homeostasis, stimuli, growth, development

Paracrine and Autocrine Signaling

Target cells lie near secreting cells - short distance diffusion

- Regulates blood pressure, nervous system function, reproduction

Autocrine - the target cell is secreting cell

Synaptic Signaling

synapses (part of neuron) secrete neurotransmitters to target cells - short distance diffusion

Neuroendocrine Signaling

neurosecretory cells secrete neurohormones into the bloodstream

3 types of hormones

Polypeptides (water-soluble) - cant diffuse across membrane, bind to surface receptor

amines (water-soluble) - cant diffuse across membrane, bind to surface receptor

steroids (lipid-soluble) - diffuse across membrane to cytosol

Pheromones

external hormone

- marking food trails

- defining territories

- warning of predators

- attracting potential mates

Hypothalamus

brain region controlling neuroendocrine signaling, hormone synthesizing

Pituitary gland

endocrine gland at the base of the brain

- Posterior pituitary

- Anterior pituitary

Posterior pituitary

extension of hypothalamus

- secretes hormones directly to bloodstream

- ADH (regulate water) and Oxytocin (milk)

Anterior pituitary

endocrine gland

- secret tropic hormones (tropins), release other hormones

Thyroid Regulation

hormone cascade pathway (trophic effects)

stimulus -> Hypothalamus -> TRH -> anterior pituitary -> TSH -> Thyroid glands -> T3 and T4 hormones -> Response

Tropisms

plant response toward/away from stimulus

Auxin

hormones, promote elongation in the tip

- Apical dominance (inhibit axillary buds), less bushy

de-etiolation

greening - response to light after a long period of insufficient light

Acid growth hypothesis

Auxin stimulates H+ pumps in membrane -> lower pH in cell wall -> expansins enzymes -> break cross-links (H-bonds) between microfibrils -> loosening the wall's fabric -> elongation

Plant hormones

abscisic acid (ABA), auxin, cytokinins, ethylene, gibberellins

abscisic acid (ABA)

Counter growth hormones

- close stomata, conserve water when drought

cytokinins

- stimulates axillary buds

- promote cell division, cytokinesis in root and shoot.

Gibberellins

cell division, stem elongation, fruit growth

seed germination (synthesis of hydrolytic enzymes to digest starch, proteins -> produce nutrients)

Ethylene

Mechanical stress

- Triple response

o stem elongation is slowed

o stem thickens

o stem grow horizontally

+ ein mutant (ethylene but no triple response)

+ ctr mutant (no ethylene but triple response)

leaf abscission, senescence (cell death)

- conserve nutrients

fruit ripening (positive feedback)

- "One bad apple spoils the bunch"

Photosynthesis

Light rxn + Calvin cycle

Light rxn (Light + H2O -> ATP, NADPH, O2)

in thylakoid membrane

- E from light excited e- (from H2O splitting, O2 released) PSII -> ETC -> PS1 -> NADP+ forming NADPH.

- e- moves down ETC released E to pump H+ to thylakoid space. ATP synthases move H+ down gradient, forming ATP.

Calvin Cycle (ATP, NADPH, CO2 -> sugar)

in the stroma

Carbon Fixation

- Rubisco adds 3 CO2 to organic molecule RuBP -> G3P (using ATP and NADPH)

Reduction & Sugar Formation

- Some G3P -> Glucose

- ATP, NADPH -> ADP, NADP+

- 6 CO2 form 1 Glucose.

Regeneration

Some G3P -> RuBP

Respiration

glucose -> 2 pyruvate -> acetyl CoA

Krebs Cycle

- NAD+ and FAD + e- and H+ -> NADH and FADH2

Oxidative Phosphorylation

- NADH and FADH2 'carry' H ions and e- to ETC

- O2 + H+ and e- -> H2O

- ETC passes e- down, release E gradually (no combust), pump H+ to intermembrane space

Chemiosmosis

- ATP synthases move H+ down gradient, forming ATP.

Autotroph (CO2 as carbon source)

Photoautotroph - light as E source (plants)

Chemoautotroph - chem as E source

Heterotroph (organic compounds as carbon source)

Photoheterotroph - light as E source

Chemoheterotroph - chem as E source (animals)

Role of O2

Obligate aerobes require O2

Obligate anaerobes poisoned by O2, live by fermentation, alternate e- acceptors (NO3, SO4)

Facultative anaerobes can use O2 or not

Prokaryote

bacteria and archaea, no nucleus

cell wall

maintain shape, protection

made of cellulose (plants) or chitin

bacterial have peptidoglycan -> target of antibiotics

Capsule

Covers the cell wall

adhere, defense

Plasmid

smaller ring of independent DNA

hypertonic environment

more "salt" outside -> cell shrinks

salt can be used to preserve foods

Gram-positive (purple)

simple structure

thick layer of peptidoglycan

less toxic.

Gram-negative (red)

complex structure

less layer of peptidoglycan, between 2 membranes

outer membrane contains lipopolysaccharides (carbohydrates bond to lipids)

Asexual reproduction

binary fission (Duplicate chromosomes -> 2 cells)

variation in prokaryotes

short generation times + large populations

metabolic functions of prokaryotes

infoldings of the plasma membrane

Endospores (thick coat, resistant cell)

bacterial dormancy - survive harsh conditions

Fimbriae

Short hair-like appendages - stick to surface

Pili (Sex pili) is longer, allow DNA exchange (Conjugation)

taxis

Move toward/away from a stimulus.

Flagella

dozens of different proteins form a motor (rings embedded in plasma membrane), hook, filament.

movement

Movement of prokaryotes

Running mode: counterclockwise rotation of flagella - move straight

Tumbling mode: clockwise rotation of flagella - change direction

Origins of Flagella

proteins added to an ancestral secretory system

Biofilms

Colonies of bacteria that adhere together to surfaces.

Metabolic cooperation

Nitrogen recycling

N-fixing: N2 -> NH4+

Nitrifying: NH4+ -> NO2- + NO3-

Denitrifying: NO3- -> N2

Microbes Mutualisms - plants and rhizobium bacteria

Plants supply sugar and shelter

rhizobium bacteria fix N2 for plants root.

Microbes Mutualisms - human

Healthcare

- Antibiotics, proteins (insulin), food supplements (probiotics)

Agricultural technology

- Clean oil spills, make transgenic plants

Industry

- Food production (yogurt, cheese), break down sewage, change to DNA

Waste -> fuel

essential

Water (dissolve, regulate temp)

minerals (bones, nervous activity)

protein (hormones, enzymes, tissues)

carb (energy)

fat (long-term energy)

vitamin (growth, facilitate nutrients)

ingestion

-suspension - filter food from water

substrate - live on and eat their food source

Fluid - suck nutrientrich fluid from hosts.

Deposit - sift to eat

Bulk - Large amounts food - most animals.

Intracellular digestion

lysosomes hydrolyze food inside food vacuoles

pinocytosis (liquid) and phagocytosis (food)

simple animal digestion

gastrovascular cavity (digestion + circulation)

complex animal digestion

alimentary canal (mouth + anus)

oral cavity digestion

teeth chew food

Salivary glands release saliva - contains amylase - break down starch, glycogen

pharynx -> esophagus -> stomach

Stomach digestion

chyme (food + gastric juice)

Gastric glands:

- Mucous cells - secrete mucus

- Chief cell - produce pepsinogen - inactive form of pepsin

- Parietal cells - secrete HCl

Small Intestine digestion

most enzymatic hydrolysis

Duodenum

- chyme + digestive juices from pancreas, liver, gallbladder, small intestine

- Pancreas produces

sodium bicarbonate - neutralizes acid

enzymes aid digestions

Small Intestine absorption

jejunum and ileum

- villi and microvilli increase absorption

amino acid and sugar carried away by blood

fat carried away by lymph

Fat absorption

Liver made Bile, stored in the gallbladder

- Bile salts digest fats

fat -> triglycerides by Bile salts

Lipase convert triglycerides -> fatty acids + monoglycerides -> diffuse into epithelial cells -> reform triglycerides -> Chylomicrons, carried away by lymph.

Large Intestine absorption

cecum - plant fermentation

colon - absorb water, house bacteria produce vitamin

rectum - store Feces

Dental Adaption

Carnivores

- Large, pointed incisor, canines - rip off preys

- Molar, premolar shred food

Herbivores

- Broad, ridged molar and premolar - grind plants

- Small, incisor and canines

Omnivores

- 6 molar crushing, 4 premolar for grinding

- 4 incisor for biting, 2 canines for tearing

Mutualistic Adaptations

Giant tubeworms - no digestive system - Rely on mutualistic bacteria

Rabbits and rodents pass food twice

Herbivores - can't digest cellulose -> fermentation chambers - mutualistic microorganisms digest cellulose

Herbivores fermentation chambers

Chewed food -> rumen and reticulum, mutualistic microorganisms digest cellulose

rechews cud from the reticulum -> further breaking down fibers

re-swallowed cud -> omasum, water removed

-> abomasum for digestion

obtains nutrients from the grass and mutualistic microorganisms.

Epithelial Tissue

Covers outside of the body

lines the organs

cavities within the body

points of exchange

Circulatory Systems

circulatory fluid

interconnecting vessels

heart

open circulatory system

Hemolymph bathes the organs directly.

No distinction between blood and interstitial fluid.

closed circulatory system

blood confined to vessels

distinct from the interstitial fluid

Fish gills

thin epithelium layer

gas exchange into blood capillary

countercurrent exchange system

-> Gas exchange over entire length -> effective

trachael system in insects

branching tubes throughout the body

short distance - no circulatory system - supply O2 directly to cell

Lungs

Air -> alveoli (air sacs), gas exchange occurs with blood capillaries

Lung diseases

Pulmonary edema - long diffusion distance

Emphysema - alveoli destruction

Fibrotic lung disease - thicken alveolar membrane

Breathing in birds

1 direction only

2 cycles of inhalation and exhalation required

pressure breathing

Positive - force air (gulp) to lungs - frogs

Negative - pull air (breath) to lungs

hemoglobin

iron-containing protein, carry 4 O2

Diving Mammals

high blood-to-body volume ratio

store O2 in their muscles - myoglobin proteins (more O2 affinity)

conserve O2 by

- Change buoyancy -> glide routing blood to vital tissues

- fermentation to produce ATP

Osmoconformers

iso-osmotic with surroundings, do not regulate osmolarity

Osmoregulators

control internal osmolarity

Salt water - dehydrating, salt gain

-> drink water and actively excrete salt

Freshwater - salt loss, water uptake

-> actively uptake salt, excrete water (urine)

Excretion

get rid of N waste

- NH3 (fish) - require water

- Urea (mammals)

- Uric acids (birds, insects)

Excretory process

Filtration: Filter body fluids -> filtrate

Reabsorption: Reclaiming valuable solutes

Secretion: Add wastes to the filtrate

Excretion: N wastes is released

Evolution of Excretory Systems

Protonephridium - flat worm - Excrete a dilute fluid

Metanephridia - earthworm - collect coelomic fluid, produce dilute urine

Malpighian Tubules - insects/arthropods - wastes as dry matter

Kidney - Vertebrates

Kidneys

CORTEX

- Proximal tubule - discrete toxins / reabsorb ions, water, nutrients/ maintain pH

- Distal tubule - selectively discrete toxins/absorb ions, water, nutrients/maintain pH

MEDULLA (OUTER + INNER)

- Descending Limp/Loop of Henle - reabsorb water

- Ascending Limp/loop of Henle: reabsorb NaCl

- Collecting duct - reabsorb water, NaCl

Circulatory system terms

ARTERIES (blood out) -> ARTERIOLES -> CAPILLARIES -> VENULES -> VEINS (blood return)

ATRIA - RECEIVE

VENTRICLE - PUMP

Single circulation

2 chambers - atria and ventricle

1 pump 1 circuits - in fish

Double circulation

2 pumps 2 circuits

Pulmonary/pulmocutaneous circuit - to lungs

Systemic circuit - to organs

amphibians circulation

3 chambers - 2 atrium, 1 ventricle

Incomplete ventricle: shut off blood flow to lungs when under water while continued blood flow to organs.

blood vessels

capillaries

- small, thin wall

- Blood flows through only 5-10% at any given time

Arteries

- medium-sized

- Aorta: biggest

Veins

- larger-sized due to smaller muscle and tissues.

- Have valves - prevent blood backflow

- vena cava: biggest (superior - lung, inferior - organs)

mammalian heart

4 chambers: 2 atria and 2 ventricles

Systole - heart contraction - pump

Diastole - heart relaxed - receive

The Cardiac Cycle - 1 Systole 1 Diastole

Atria, ventricle diastole

-> blood flow veins -> atria -> ventricle

Atria systole, ventricle diastole

-> blood flow atria -> ventricle

Atria diastole, ventricle systole

-> blood flow ventricle -> arteries

Sinoatrial (SA) node (pacemaker)

sets rate and timing at which cardiac muscle cells contract

can be controlled by hormones/nervous system to influence heart rate

Sphincter

ring muscle at the entrance to capillary beds

Open/close -> regulate blood flow to capillary

Blood composition

plasma - ions, proteins

cell - red blood, white blood, platelets

blood clotting

Clotting factors -> fibrin

Platelets - form sticky plug

platelets + blood + fibrin strands -> clot

Lymphatic system

immune system

returns fluid leaks (lymph) from capillary

- Blood pressure drive fluid out of capillaries

- Blood proteins pull fluid back (osmotic pressure)

Transport in Plants root

Apoplastic route - root hair passively uptake soil solution to Apoplast (cell wall)

Symplastic route - water, minerals that cross plasma membrane.

Transmembrane route - water, minerals transported from Apoplast -> protoplasts of cells of Epidermis & Cortex -> Symplast.

Endodermis

- Casparian strip, waxy, control entry to Stele. Only minerals in Symplast or minerals in endodermal cell can pass (no Apoplast)

Transport in the Xylem - cells in Stele discharge water, minerals -> Apoplast -> xylem -> shoot (bulk flow)

Stomata

Stomatal opening

Light triggers active transport of K+ into the vacuoles

Water moves into the vacuoles, following K+

The guard cells expand, stoma opens

Stomatal closing

No light, K+ pumping stops, K+ moves out

Water moves out of the vacuoles

The guard cells shrink, stoma closes

Xylem bulk transport (Cohesion-Tension Hypothesis)

Transpiration, Cohesion and Adhesion, root pressure

Transpiration

Evaporative cooling

negative pressure gradient, draws up water, minerals from roots

Allows gas/water exchange - photosynthesis

transpiration in mesophyll cells -> air-water interface more curved -> high surface tension -> negative pressure potential -> draw water from xylem

Cohesion, Adhesion

cohesion: water bonds water

adhesion: water bonds anything else

H-bond

Root pressure (weak)

Water and minerals absorption -> positive pressure