Final Exam Flashcards
what range does endocrine signal
long distance
what range does juxtacrine signal
adjacent
what does paracrine signal
close proximity
what does autocrine signal
self stimulating
what is being signaled?
hormones, lipids, proteins, sometimes gases.
what is metabolism
The sum of all reactions, catabolic and anabolic reactions.
Refers to all the bodily activities and chemical reactions in an organism that maintains life.
what is catabolic reactions
breaks down compounds; generates energy (ATP).
what are anabolic reactions
creating compounds; consumes energy (ATP).
what is metabolism related to
body temperature
what is metabolic rate
Rate at which an organism uses energy to power these reactions.
what does leptin do
a hormone that is secreted in order to feel satiated; long term.
what does ghrelin do
a hormone that is secreted before eating for salivation; short term.
what is the metabolic pathway
Protein A to Amino Acid B through enzyme X, so on and so forth by enzyme Z and Y until we get the final product.
pathway for glucose
Glucose is broken down, releasing ATP through each step, resulting in CO2 and H2O.
what two phases are used for nutrient utilization
absorptive and postabsorptive
what is the absorptive phase
occurs when ingested nutrients enter the bloodstream from the GI tract.
Some of the ingested nutrients are used for immediate energy needs, others stored.
About 4 hours.
what is the postabsorptive phase
occurs when the GI tract is empty of nutrients, and body’s stores are used.
About 12 hours, but can go up to 2 weeks.
what are the main sources of nutrition
carbohydrates, lipids, and proteins.
Carbohydrates: mostly glucose; sometimes other sugars.
Lipids: Triglycerides; sometimes other fats.
Proteins: amino acids are broken down into ATP if starving; amino acids that are taken in are broken down into triglycerides.
what are the two most important metabolic organs
pancreas and liver
what does the liver do metabolically
filters toxins that are consumed; stores glucose in the form of glycogen; generates bile that emulsifies toxins to be secreted.
what does the pancreas do metabolically
makes and secretes key digestive enzymes, like amylase; also makes and secretes bicarbonate that neutralizes stomach acid.
what do glycosidic bonds do
Glycosidic bonds alpha 1 and 4 break down glycogen; alpha 1 and 6 break down starch.
what sugar does the skeleton store
glycogen
what two organs need energy constantly
heart and brain
what energy will the brain use
only sugar
what energy will the heart use
any energy
difference between liver and muscle sugar retention
liver shares the sugar while the muscles keep it.
what happens when glucose is broken down
made into maltose, which is 2 glucoses
what is a sucrose molecule made from
fructose and glucose
what is a lactose molecule made from
glucose and galactose
what sugars are disaccharides
maltose, sucrose, and lactose
which sugars are monomers
glucose, fructose, galactose
what happens to the sugar the liver cannot store
converted into fat
what is most sugar made into
used to synthesize ATP
what are major sugar polymers
glycogen and starch
what is lipase
an enzyme that digests fats
what is a micelle
aggregation of lipids in water (3 carbons with a phosphate attachment)
what are lipoproteins
store triglycerides, which together are called chylomicron, which can be released into the lymph vessels/bloodstream through exocytosis.
how are triglycerides digested
too large to diffuse across the plasma membrane of intestinal epithelial cells.
Digested into monoglycerides and fatty acids.
Diffuse into intestinal epithelial cells.
Resynthesized
what happens to absorbed amino acids
Taken up by all body cells.
Used to synthesize proteins.
Excess amino acids not stored as protein.
Excess are converted by liver cells into fatty acids and then triglycerides.
Waste, especially urine, is nitrogenous due to excess amino acids.
Properties of vitamins, minerals, and water
Do not require digestion.
Absorbed in complete form.
fat-soluble vitamins follow pathways for fat absorption.
Small amounts of water are absorbed in the stomach but most in the small intestine.
what are the two types of vitamins and minerals
water soluble and oil/lipid based
examples of water soluble and lipid based vitamins/minerals
Water soluble: vitamin B and C (all versions).
Oil/Lipid: A, D, E, K; absorption is the same as lipids.
what happens during the postabsorptive phase
Synthesis of glycogen and fats slows and breakdown begins.
the liver produces glucose to maintain blood-glucose concentrations through the degradation of glycogen (glycogenolysis) and the synthesis of glucose (gluconeogenesis) from lactate, pyruvate, glucogenic amino acids (principally alanine), and glycerol.
Using fat instead of glucose for energy (glucose sparing).
5 mechanisms for generating glucose in bloodstream
Liver breaks down glycogen (glycogenolysis) and converts it into glucose;
Muscles harvest their own glycogen and glucose; also use glycogenolysis.
Gluconeogenesis is when cells make their own glucose through broken down lipids (lipolysis) to turn it into glucose.
Breakdown of proteins.
Glucose sparing: Fatty acids can be catabolized by many cells, especially aerobic muscle fibers.Glucose needs to get through the GLUT protein on PM. There are 14 different versions, but GLUT 1, 3, and 4 are the most important. Each GLUT has different glucose affinities. 4 has low affinity for glucose and is the only one requiring insulin, muscle and fat; GLUT 1 and 3 have high affinity. Insulin then binds to the receptor when glucose is detected in the body. Which will send a signal to the nucleus which will produce more activity for the GLUT proteins. Insulin helps digest the sugar.
what do neurons have a high affinity for
GLUT transporters
what does the rest of the body have a low affinity for
GLUTs
what is the definition of glucose sparing
the neurons and brain will always get priority for glucose. Whatever is left over is for the body.
where is insulin made
pancreas
what inhibits glycogenolysis and gluconeogenesis in the liver.
insulin
What do GLUTs do
GLUTs transport glucose across the plasma membrane by means of a facilitated diffusion mechanism.
what stimulates glucose diffusion into cells
insulin
what is a calorie
amount of heat required to raise the temperature of 1 gram of water 1 degree celsius.
Kcals are commonly used.
How are carbohydrates digested, absorbed and stored?
absorbed into the small intestine. Once they’re absorbed, they’re processed even more by the liver and stored as glycogen. Other glucose is moved through the body by the bloodstream. The hormone insulin is released from the pancreas and allows the glucose to be used as energy.
How are lipids digested, absorbed and stored?
In the small intestines bile emulsifies fats while enzymes digest them. The intestinal cells absorb the fats. Long-chain fatty acids form a large lipoprotein structure called a chylomicron that transports fats through the lymph system.
Lipids are stored in the body in different forms such as, triglycerides, fat cells, cell membranes and lipoproteins.
How are proteins digested, absorbed and stored?
Mechanical digestion of protein begins in the mouth and continues in the stomach and small intestine. Chemical digestion of protein begins in the stomach and ends in the small intestine. hydrochloric acid and enzymes called proteases break it down into smaller chains of amino acids. The pancreas secretes digestive juices into the small intestine, and these contain more enzymes to further break down polypeptides. The body can’t store protein, so once needs are met, any extra is used for energy or stored as fat.
Describe the different mechanism that mammals (humans) use to maintain glucose
homeostasis.
Together, insulin and glucagon help maintain homeostasis, where conditions inside the body hold steady. When a person’s blood sugar is too high, their pancreas secretes more insulin. When their blood sugar levels drop, their pancreas releases glucagon to raise them.
primary function of the circulatory system is
Transport necessary materials to the cells of an animal’s body.
Transport waste products away from cells so they can be released into the environment.
what are the three types of circulatory system
gastrovascular cavity, open circulatory systems, closed circulatory systems
gastrovascular cavity properties
ascular cavity
Body cavity with a single opening.
Jellyfish, anemones, hydras.
Food is digested in the cavity and absorbed into cells.
Wastes are excreted into cavities.
All of the animal’s body cells must be located near the cavity or in slender extensions.
Muscular efforts of the cell wall increase effectiveness.
Cell wall must be thin in order for exchange.
open circulatory system properties
Arthropods and some mollusks.
Basic components: hemolymphs (mixture of blood and interstitial fluid), vessels, one or more hearts.
Vessels open into the animal’s body cavity.
closed circulatory system properties
Blood and interstitial fluid are physically separated; differ in components and chemical composition.
Larger, more active animals need a high pressure to pump blood to all body cells.
Found in earthworms, cephalopods, and all vertebrates.
Advantages/features: redirects blood; always a heart (pump); cells within blood work as a defense mechanism (immune system); has the ability to repair; when growing, more vessels also grow; can adapt to metabolism; transportation.
solutes in gas exchange
O2 and CO2
what is single circulation
Blood delivers oxygen and nutrients to the cells.
Blood picks up carbon dioxide and waste products.
Deoxygenated blood is returned by veins to the heart.
Examples: fish.
Heart valves prevent backwards flow.
what is double circulation
Major advantage of double circulation: two different blood pressures in two different systems.
CO2 blood comes from heart to lung, oxygenated by lungs, flows back into the heart, and oxygen is pumped out to the rest of the body.
The heart acts as a dual dump; still has the pulmonary and systemic pathways.
what is intermediate circulation
Two atria to collect blood.
Right atrium: blood from the body that is low in oxygen.
Left atrium: blood from the lungs that is oxygen-rich.
Pulmonary pathway: arteries go only to the lungs.
Systemic pathway: arteries go to the body.
Advantages: skin can carry out gas exchanges.
Disadvantages: CO2 reflow.
Examples: amphibians.
what is hemolymph
the major transport medium for the exchange of materials between cells, such as hormones, waste materials, and nutrients. Through its regulation of ionic and chemical composition, it maintains the proper internal environment for cells as an extracellular extension of intracellular fluids (INSECTS)
what is the atrium
heart chamber that receives blood into the heart and drives it into a ventricle, or chamber, for pumping blood away from the heart.
what is the ventricle
muscular chamber that pumps blood out of the heart and into the circulatory system.
what are the 3 components of blood
plasma, hematocrit, and buffy coat
what is the plasma
Plasma is 55% of all blood and is mostly water, but contains albumin, globular proteins (antibodies).
Gases include CO2 and O2.
Acids and bases are in the forms of molecules.
Nutrients include amino acids and sugars.
Other proteins include complement proteins (immune system).
what is the hematocrit
Hematocrit includes RBC, which is 45% of blood.
what is the buffy coat
The Buffy coat represents about 1% of blood; it contains white blood cells.
