Enzymes and Homeostasis study guide Flashcards
What are the four factors that affect chemical reactions and how do they affect the rate of these rxns?
- Temperature: At hot temperatures, the kinetic energy increases because the particles are moving faster and therefore the number of collisions increases, increasing the rxn rate. At colder temperatures, the kinetic energy decrease because the particles are moving slower, therefore decreasing the number of collisions and decreasing the rxn rate
- Surface area: Increasing the SA of a solid, increases the number of reactants that can react. Decrease the SA of a solid, decreases the number of reactants that can react
- Presence of an enzyme/catalyst: Enzymes can lower the energy of activation needed to activate the reactants. Therefore, the rate of reaction is much faster
- [ ] of the substrate: a higher [ ] of the substrate will increase the number of collisions and therefore increases the rxn rate and visa versa for a lower [ ].
What is activation energy (Ea)? How does it determine rxn rate?
The amount of energy required to make products.
The lower the Ea is, the greater the rxn because it requires less energy to transition and visa versa for a higher Ea.
How do catalysts work to speed up chemical reactions?
they lower the Ea, therefore speeding up chemical reactions
What do all enzyme names end with?
Ase
what components make up a holoenzyme
apoenzyme and co-factor (vitamin or mineral)
Define apoenzyme, co-enzyme and co-factor
Apoenzyme: the protein portion of an enzyme (inactive)
Co-factor: composed of vitamins or minerals
Co-enzyme: composed of vitamins
Give examples of co-enzyme and co-factor
co-factor
- minerals: copper, zinc, iron, magnesium, selenium
co-enzyme
- vitamins: riboflavin, niacin
define metabolism, metabolic pathway and metabolic energy
Metabolism: All series of chemical reactions occurring within your body
Metabolic pathway: A series of chemical reactions occurring within your body
Metabolic energy: cellular respiration (production of ATP)
Explain lock and key theory
A theory where an enzyme has a specific shape which allows the substrate to fit either by hydrolysis or synthesis reactions. (active site)
explain induce fit theory
a theory where some active site undergoes a slight change in shape in order to accommodate a substrate and to achieve optimum fit.
what are the factors affecting enzyme activity?
- Heavy metal
- Surface area
- Temperature
- pH
- [ ] of substrates and enzymes
- Inhibitors
Compare and contrast competitive and noncompetitive inhibitors
Compare:
- both attach to a certain site on the enzyme
- both are inhibitors
Contrast:
- competitive inhibitors are irreversible
- noncompetitive inhibitors are reversible
- competitive inhibitors attach to the enzyme’s active site and cannot be removed from the enzyme’s active site
- noncompetitive inhibitors attach to the enzyme’s allosteric site and can be removed
- competitive inhibitors halt the production of products/ the substrate’s ability to attach to the enzyme’s active site
- noncompetitive inhibitors reduce the activity of the enzyme for a limited time.
give examples of competitive inhibitors
- cyanide
- penicillin
what is negative feedback inhibition?
When “too much” of a substance results in decreased production of the same or a different substance
what is homeostasis?
the maintenance of equilibrium of the body’s internal environment in the face of changing conditions
four examples of homeostasis in the body
- body temp regulation
- blood pressure regulation
- blood pH regulation
- blood glucose level regulation
- blood salt lv regulation
why is a constant internal environment important?
so that certain chemical reactions can maintain their optimal environment and conditions to function at their best
how is homeostasis controlled
Homeostasis is maintained by negative feedback loops within the organism
Know the general components of a feedback loop
stimulus → receptor → regulatory center ↓
↑ adaptive response
what are some examples of stimuli
- chemicals
- light
- sound waves
- motion
- waves
what are the 4 type of receptors and where are they found
- Chemoreceptors, found in central and peripheral nervous system
- Photoreceptors, retina
- Mechanoreceptor, skin
- Thermoreceptor, skin
give examples of negative feedback mechanism involving in maintaining body temp
Stimulus (body temp increases above average)
Receptor (skin blood vessels dilate: blood carries heat to the skin surface)
Regulatory center (sweat glands activate)
Adaptive response (body temp decreases from sweat)
how does positive feedback differ from negative feedback
negative feedback decreases the stimulus, meanwhile positive feedback intensifies stimulus
explain the positive feedback mechanism involved during childbirth and or nursing a baby
Childbirth:
- Stimulus (head of baby begins to press against the cervix)
- Receptor (Mechanoreceptors receive the signal)
- Regulatory center (posterior pituitary gland secretes oxytocin)
- Adaptive response (uterus contracts even more to push the baby)
Nursing a baby:
- Stimulus (baby suckling on nipple )
- Receptor (Mechanoreceptors sends nerve impulses to travel to the hypothalumus)
- Regulatory center (posterior pituitary gland secretes oxytocin)
- Adaptive response (lobules in mammary glands to contract releasing the milk)
how does hormones’ help maintain homeostasis
releasing hormones in response to stimuli, that leads to negative feedback loops.
differentiate between endocrine and exocrine glands
- exocrine glands secrete substances into a duct
- endocrine glands secrete products directly into the bloodstream
what are the two general classes of hormones’
protein (peptide) & lipid (steroid) based horomones
compare and contrast on how peptide and steroid hormones’ work
Compare:
- both bind to a protein receptor
Contrast:
- steroid horomones are lipid soluble (can pass through cell membrane with ease)
- peptide horomones are lipid non-soluble (must attach to receptor to enter cell)
where is the location of the thyroid gland and what is its function?
infront of the thrachea, to produce thyroxin which assist in maintaining metabolism (increases rate of cellular respiration)
explain negative feedback loop involved in maintaining thyroxin levels and what glands and horomones are involved
- Stimulus (thyroxin lvs are low)
- Receptor chemoreceptor detects low thyroxine lvs
- Regulatory center (Hypothalamus releases thyrotropin-releasing horomones TRH)
- Regulatory center (anterior pituitary gland secretes thyroid stimulating horomone TSH in to bloodstream (endocrine))
- Adaptive response (TSH binds to receptor on cell membrane, identifies if iodine lvs are sufficient, then thyroxin is made and secreted in to bloodstream, increasing thyroxin lvs)
what is hyperthyroidism and what are the symptoms
-when your thyroid gland produces too much of the hormone thyroxine
Symptoms:
- hyperactivity
- nervousness
- irritability
- insomnia
- weight loss
- anxiety
- fast heart rate
- overheating
what is hypothyroidism and what are the symptoms
when your thyroid gland produces too little of the hormone thyroxine
Symptoms
- constant fatigue
- weight gain
- decreased body temp
- loss of hair
- slower pulse
- thickness and puffiness of skin
- low moods
- sensitivity of cold temps
- poor digestion
