Week 5 - How do we fuel our body? Flashcards
What are some examples of proteins found in the plasma membrane?
channel, carrier, ATP-powered
Channel proteins
- molecules of a certain size, shape and charge can pass through
- can be gated or non-gated
Carrier proteins
- specific binding sites
- protein changes shape to transport ion or molecules but resume original shape after transport
- uniporters (1 molecule), symporters (2 molecules, same direction), antiporters (2 molecules, different directions)
ATP-powered pumps
requires energy (ATP), against concentration gradient (allows accumilation of substances), eg sodium/potassium pump
What is diffusion?
movement of substances from an area of high concentration to an area of low concentration, down the concentration gradient, continues until there is an even distribution
What is the difference between water-soluble and lipid-soluble substances?
Water-soluble: must go through protein channels
Lipid-soluble: can diffuse through membrane
What is osmosis?
the movement of water across a selectively permeable membrane
What is osmolarity?
- the pull created on water by solutes
- measured in Osmoles/L or mOsmoles/L
What is the osmolarity of the intracellular fluid of a normal cell?
290 mOsmoles/L
Isotonic solution
same osmolarity inside and outside a cell, no net movement
Hypertonic solution
high osmolarity outside the cell, water is pulled out of the cell –> dehydration, crenation
Hypotonic solution
high osmolarity inside the cell, water is pilled into th cell –> swells, lysis
What is metabolism?
The sum of all chemical reactions in the body
What is the difference between anabolic and catabolic?
Anabolic: combine to form new substances, chemical bonds made and energy is stored, growth maintenance and repair
Catabolic: large reactant broken down to form smaller products, bonds break and energy is released
Where does glycolysis occur?
in the cytoplasm of cells
What is broken down and produced during glycolysis?
Glucose (6C) is broken down into x2 pyruvate (3C). x2 ATP and x2 NADH are produced
What is the difference between oxygen available and oxygen not available with pyruvate?
Available: pyruvate moves to second stage
Not available: pyruvate converted to lactic acid
Where does the citric acid cycle occur?
matrix of mitochondria
What occurs in the citric acid cycle?
each pyruvate is concerted to acetyl CoA. CO2 and NADH is released for each pyruvate. After this, acetyl CoA is broken down into a 4C molecule, producing x2 CO2 each and one FADH2 each
What happens during oxidative phosphorylation?
NADH and FADH2 donate electrons, releasing hydrogen ions. The hydorgen ions join with oxygen to form water. 32-24 ATP molecules are produced
What happens to fatty acids during cellular respiration?
beta oxidation to form acetyl CoA –> enters citric acid cycle
What happens to amino acids during cellular respiration?
cencerted to intermediate compounds of CHO
