BIO 120 - Unit 3

Identify features of the diabetes mellitus epidemic

elevated levels of glucose in the blood, issues with insulin secretion/response

Explain what makes a chemical messenger a “hormone”, and how hormones differ from other types of chemical messengers

Hormones are secreted from endocrine gland into the blood and travels to target cells to trigger specific responses

Explain the differences between a steroid, protein, and amino acid derivative (i.e., modified amino acid) hormones

Proteins are made of amino acids, often species-specific (membrane bound), amino acid derivatives are modified amino acids (membrane bound), steroids are modifications of cholesterol (intracellular)

Understand differences between membrane-bound and intracellular receptors (including their location in/on the cell and their function when activated).

membrane bound receptors are located on cell surface and signal transduction takes place. Intracellular receptors take place within the cell and the hormone-receptor complex acts as a gene transcription factor

Identify the general properties of hormone receptors; understand how the mechanisms of action differ for intracellular vs. membrane-bound receptors

Describe how the interplay of insulin and glucagon secretion and action regulate blood glucose homeostasis in mammals. Know what stimulates release of each hormone, the cell types they’re secreted from, and explain how each hormone affects blood glucose levels.

If glucose levels are too high, pancreas secretes insulin which leads to the synthesis of glycogen which lowers glucose levels. if glucose levels are too low, pancreas secretes glucagon which leads to the catabolysis of glycogen which increases glucose levels

Explain the difference between glucose transporters that are regulated by specific signals (e.g., GLUT4) and those that are not regulated by specific signals (e.g., GLUT1, GLUT2,GLUT3).

regulated glucose transporters (glut4) require a signal to be inserted in the membrane while other transporters are always present in the membrane (glut1-3)

Articulate specific actions of insulin on liver, skeletal muscle, and adipose tissue cells.

liver: activation of signal transduction and stimulates glycogenesis
adipose tissue cells: signaling cascade stimulates lipogenesis
skeletal tissue cells: glycogenesis, amino acid uptake, stimulation of protein synthesis

Differentiate between type I and type II diabetes mellitus.

type 1 does not secrete enough insulin, type 2 doesn’t respond properly to insulin (“insulin resistance”)

Explain what is meant by “insulin resistance” in type II diabetes and explain what this means from an endocrine signaling perspective.

cells are not as responsive to the effects of insulin

Describe the physiological and health consequences of chronic hyperglycemia, as is seen in type II diabetes.

macrovascular complications: build up of plaque and narrowing arteries so increased heart pressure
microvascular complications: capillaries through body, especially eyes, are weakened
neuropathy: nerve cell death

Identify the primary treatment approaches to type II diabetes and explain why exercise is particularly helpful for regulating blood glucose.

nutritional diet and exercise bc exercise stimulates insertions of glut4 in the membrane

Identify general functions of blood and, in particular, red blood cells.

Describe the importance of respiratory pigments in oxygen transport.

Understand what dictates the shape of a hemoglobin-oxygen equilibrium curve.

Explain what is meant by hemoglobin’s oxygen affinity and draw a hemoglobin-oxygen equilibrium curve that illustrates hemoglobin with a high affinity for oxygen and one that illustrates hemoglobin with a low affinity for oxygen.

define glycogenesis

glycogen production

define lipogenesis

production of triglycerides

Explain the concept of facilitated diffusion and  the role that membrane proteins play in facilitated diffusion

What are the categories of chemical messengers?

autrocrine signals, paracrine signals, neural signals, endocrine signals, neuroendocrine signals

What do autocrine signals do

act on same cell that secretes them

what do paracrine signals do

diffuse locally and act on nearby cells

what do neural signals do

diffuse a short distance between neurons

what do endocrine signals do

carry hormones between distant cells by blood or other body fluids

what do neuroendocrine signals do

hormones (neurohormones) are released from neurons

what do hormones do

direct developmental processes, coordinate responses to stressors, maintain homeostasis

what glucose transporters is most abundant in muscles

glut4

what is gestational diabetes

other hormones present during pregnancy make insulin less effective (insulin resistance)

What is a respiratory pigment’s P50 a measure of? How do you determine the actual value from a hemoglobin-oxygen equilibrium curve?

p50 is a measure of O2 affinity. the value is found where the hemoglobin saturation with o2 is 50%. The pO2 at that point is the p50 value

Explain how myoglobin differs from hemoglobin, where it is found, and what its function is. ​

very high affinity for o2 (or can’t bind to o2 from Hb), found intracellularly in muscle cells (skeletal/cardiac), only has one subunit, may serve as an o2 reserve

what are the major vessels found in closed circulatory systems

arteries, arterioles, capillaries, venules, and veins

what are arteries

carry blood away from heart; smooth muscles allows regulation (add form)

what are arterioles

mini arteries that follow arteries and play major role in smooth muscle (add form)

what are capillaries

exchange occurs here (add form)

what are venules

take blood back to heart (add form)

what are veins

return blood to heart; little smooth muscle; valves prevent backflow (add form)

Explain the significance of the large cross-sectional area and low velocity of blood flow found in blood capillaries

Understand what cardiac output is and what affects it. ​

why is it good that Hb can reversibly bind

it makes it good carrier/transporter

what is po2

amount of oxygen dissolved in blood plasma

what is the relationship between p50 and o2

when p50 is lower, Hb has a greater affinity for o2