Exam 1- SG Flashcards
What are examples of negative and positive feedback?
Negative: blood pressure
Positive: birth
How are negative and positive feedbacks distinct
Positive: Stopped by physical event
Negative: Stopped by a physiological regulation
Be able to identify or describe examples of negative and positive feedback. What is the biological basis of diabetes? In your answer include terms such as insulin, glucagon, glucose, carrier-mediated facilitated transport, glycogen, glucose blood levels, pancreas, homeostasis and feedback mechanisms.
Normal Blood Sugar Regulation:
After eating, glucose blood levels rise, pancreas releases insulin, which allows cells to absorb glucose via carrier-mediated facilitated transport.
Excess glucose is stored as glycogen in the liver. When blood glucose drops, glucagon is released to break down glycogen into glucose (glycogenolysis), restoring balance.
Diabetes occurs when the bodys normal feedback mechanisms for regulating blood glucose levels break down
In detail, compare/contrast carbohydrates, lipids, proteins
-What are each group of molecules made of?
-What do they do?
-How are they broken down or formed?
-Be able to list or identify examples of each group.
Carbs:
Made of monosaccharides
Function: Primary energy source, structural support
Formed by dehydration synthesis, break down by hydrolysis
Startch
Lipids:
Made of Glycerol and fatty acids
Function: Long term energy storage, cell mem structure
Formed by fatty acid and glycerol linking breaks by lipolysis
Fats and oils
Proteins:
Made of Amino acids
Function: Structural support and enzyme transport
Built up by peptide bonds, break down by proteolysis
Hemoglobin
Define protein denaturation
- Globular proteins unfold and lose functional 3D shape
- Can be caused by decreased pH or increased temp
What are different protein structural levels?
Primary: Amino Acid sequence
Secondary: Alpha helices or beta pleated sheets (H-H bonds)
Tertiary: Super imposed folding of secondary structures (S-S bonds)
Quaternary: polypeptide chains linked together in specific manner (covalent bonds)
What is an enzyme?
Globular proteins that act as biological catalysts
- enzymes regulate and increase speed of chemical reactions
How do enzymes effect activation energy
They reduce activation energy
What are the differences between competitive and non-competitive inhibition?
Comp:
- Inhibitor competes with substrate for binding to enzyme; or I blocks S from binding to E
- Reduces enzymes affinity for the substrate
Non:
- I binds at another site other than active site
-No reduced affinity
Why is the mitochondrion important to metabolism?
It is the primary site for cellular respiration, which generates ATP
Define metabolism
sum of all chemical reactions in the body
What is the difference between anabolic and catabolic reactions?
Catabolism – The breakdown of complex molecules into simpler ones, releasing energy
Anabolism – The building of complex molecules from simpler ones, requiring energy.
What are two main mechanisms to generate ATP?
Substrate level phosphorylation
Oxidative phosphorylation
What is Substrate level phosphorylation and where does it occur
High energy phosphate groups are directly transferred from phosphorylated substrates to ADP
Occurs twice in glycolysis, once in Krebs
What is oxidative phosphorylation and where does it occur
ATP is produced using energy from electrons transferred through the electron transport chain (ETC) in the mitochondrial inner membrane.
What are the three stages of metabolism and where do they each occur?
- Glycolysis: Cytoplasm
- Krebs Cycle: Mito Matrix
- ETC: Inner mito membrane
What is meant by oxidation, reduction, and a redox reaction?
Oxidation: Loss of electrons and energy
Reduction: Gain electrons and energy
Redox reactions: reaction where both oxidation and reduction occurs
What is cellular respiration?
Cellular respiration is the process by which cells convert nutrients (usually glucose) into energy in the form of ATP
How are carbohydrates metabolized?
oxidation of glucose
goes through the steps of cellular respiration
What is glycolysis? Can it occur in an anaerobic environment? Where does it occur?
Break down of glucose
Yes it can
cytoplasm
What is the purpose of each step? What is gained by each step?
Glycolysis: break down glucose; generate small amts of ATP and NADH
Krebs: Produce, ATP, FADH and NADH, release CO2
ETC: Create a proton gradient, driving production of lots of ATP
What is the Cori cycle
- Glyconeogensis
- Cycle that helps to remove lactic acid
What are NAD+ and FAD? How are they important?
Electron carrier, Coenzymes and they carry energy in the form of bond energy
Be able to use and apply terms such as glucogenesis, glycogenesis, glycogenolysis
Gluconeogenesis: New glucose formation
Glycogenesis: Glycogen formation
Glycogenolysis: Glycogen breakdown
How is glucose converted into fat?
Glucose is converted to fat through lipogenesis. When the body has excess glucose, the tissues are full, the liver is always full so the excess gets stored as fat in adipose tissues.
What is in the plasma membrane?
Plasma membrane is made up of phospholipids, there are channel proteins as well as the cytochrome complex, selectively permeable
What are the three types of membrane junctions?
Tight Junction, Desmosomes, and Gap Junctions
Tight Junctions
- Prevent fluids and most molecules from moving in between cells
- Waterproofing
- Useful in body in the bladder, don’t want waste products or urine to get where its not supposed to be
Gap Junctions
- Allows electrical signals to be passed quickly from 1 cell to another
- Cells function together as a functional unit
- Helpful in body in the heart or in the bladder for rhythmic contractions
Desmosomes
- Rivet like cell junction formed when linker proteins of neighboring cells interlock like teeth of zipper
- Allows for their to be give under tension so they wont tear
- When snapping them together there can be some liquid movement
What are the subcategories of Passive Transport
simple diffusion, facilitated diffusion, osmosis
What is passive and active transport
Active: energy (ATP) is required
Passive: no energy is required
What is simple diffusion
When ions move from an area of high concentration to low concentration
What is facilitated diffusion
Diffusion where the ion is helped through, think hands, they grab it and then help it through
What is osmosis
based on the concentration of solutes to move water, water always move to higher solute
Describe variables that can increase or decrease rate of molecular movement
Concentration
Molecular size
Temp
how does concentration effect the rate of molecular movement
Greater the difference of concentration between 2 areas, the faster diffusion occurs
how does molecular size effect the rate of molecular movement
Smaller molecules diffuse faster
how does temp effect the rate of molecular movement
Higher temps increase kinetic energy which results in faster diffusion
How is equilibrium reached with molecules
when there is no net movement of molecules in 1 direction only
