Week 5 - How do we fuel our body?

Question 1

What are some examples of proteins found in the plasma membrane?

Answer 1

channel, carrier, ATP-powered

Question 2

Channel proteins

Answer 2

• molecules of a certain size, shape and charge can pass through
• can be gated or non-gated

Question 3

Carrier proteins

Answer 3

• 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)

Question 4

ATP-powered pumps

Answer 4

requires energy (ATP), against concentration gradient (allows accumilation of substances), eg sodium/potassium pump

Question 5

What is diffusion?

Answer 5

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

Question 6

What is the difference between water-soluble and lipid-soluble substances?

Answer 6

Water-soluble: must go through protein channels

Lipid-soluble: can diffuse through membrane

Question 7

What is osmosis?

Answer 7

the movement of water across a selectively permeable membrane

Question 8

What is osmolarity?

Answer 8

• the pull created on water by solutes

- measured in Osmoles/L or mOsmoles/L

Question 9

What is the osmolarity of the intracellular fluid of a normal cell?

Answer 9

290 mOsmoles/L

Question 10

Isotonic solution

Answer 10

same osmolarity inside and outside a cell, no net movement

Question 11

Hypertonic solution

Answer 11

high osmolarity outside the cell, water is pulled out of the cell –> dehydration, crenation

Question 12

Hypotonic solution

Answer 12

high osmolarity inside the cell, water is pilled into th cell –> swells, lysis

Question 13

What is metabolism?

Answer 13

The sum of all chemical reactions in the body

Question 14

What is the difference between anabolic and catabolic?

Answer 14

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

Question 15

Where does glycolysis occur?

Answer 15

in the cytoplasm of cells

Question 16

What is broken down and produced during glycolysis?

Answer 16

Glucose (6C) is broken down into x2 pyruvate (3C). x2 ATP and x2 NADH are produced

Question 17

What is the difference between oxygen available and oxygen not available with pyruvate?

Answer 17

Available: pyruvate moves to second stage

Not available: pyruvate converted to lactic acid

Question 18

Where does the citric acid cycle occur?

Answer 18

matrix of mitochondria

Question 19

What occurs in the citric acid cycle?

Answer 19

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

Question 20

What happens during oxidative phosphorylation?

Answer 20

NADH and FADH2 donate electrons, releasing hydrogen ions. The hydorgen ions join with oxygen to form water. 32-24 ATP molecules are produced

Question 21

What happens to fatty acids during cellular respiration?

Answer 21

beta oxidation to form acetyl CoA –> enters citric acid cycle

Question 22

What happens to amino acids during cellular respiration?

Answer 22

cencerted to intermediate compounds of CHO