Unit 2 - Cell Respiration Flashcards

Question

State the equation for cellular respiration (aerobic) and photosynthesis

Answer 1

* Transport proteins (a channel or a carrier) * Recognition proteins (identifies cell; an antigen is an example) * Receptor proteins (metabolism behaviour, message receiver) * Adhesion proteins (leak-proofing, communication)

Answer 2

* Outer mitochondrial membrane * Inner mitochondrial membrane * Inter-membrane space/compartment * Matrix * Cristae (inner folds that increase SA to benefit the electron transport system)

Answer 3

* An "electrogenic pump" (electric potential) found in animals * Found within membranes * Function: get rid of 3 Na⁺ and take in 2 K⁺ * Pump gets its energy from chemical energy in which ATP is hydrolyzed

Answer 4

* Located in the gastric glands of the stomach * Pumps H⁺ into the lumen of the stomach * Combines with Cl^- to form HCl, allowing for breakdown of proteins * Also pumps K⁺ into the mucosa * Since both ions move against the concentration gradient, ATP is required * The pump can over-pump and lead to too much stomach acid, resulting in ulcers. Antacids lower H+ and other drugs slow the pump

Answer 5

* Another electrogenic pump that actively transports hydrogen ions (protons) * Major role in membranes of mitochondria and chloroplasts

Answer 6

It is a process in which two substances are simultaneously transported across a membrane by one protein: * Na⁺ can renter the cell, but only when it is **coupled** by glucose * The sodium-potassium pump works with glucose by providing Na⁺ for it

Answer 7

**Symport**: the movement of 2 substances together in the same direction (ex., Na⁺ and glucose) **Antiport:** the movement of 2 substances together in the opposite direction (ex., Na⁺/K⁺pump)

Answer 8

The theory says that early eukaryotic cells engulfed aerobic bacteria, but due to their plasma membrane, they were not digested. The bacteria then continued to perform aerobic respiration, providing excess ATP to the cell and reproducing independently within the cell.

Answer 9

Mitochondria and chloroplasts have features that differ from other organelles, relating them to bacteria: 1. They are double-membraned 2. The chemistry of their inner membrane resembles eubacteria plasma membranes 3. They have their own DNA with remnants of eubacterial chromosomes and coding sequences for proteins and RNA which resemble bacterial genes 4. They replicate their own DNA and undergo division independently of their host cell

Answer 10

Glycerol bonded to phosphate head (hydrophilic) with two fatty acid tails (hydrophobic) It is produced via a condensation reaction

Answer 11

Anabolic: ribosomes Catabolic: mitochondria

Answer 12

Carbohydrates are the first nutrients most organisms catabolise for energy, but, when necessary, most organisms can also metabolism proteins, lipids, and even nucleic acids.

Answer 13

1. Digested into amino acids 2. Amino groups are removed via deamination, converting the groups in NH₃ (a useful by-product in plants but waste in animals) 3. The remaining portion of the amino acids are converted into components or glycolysis of the Krebs cycle, depending on its type

Answer 14

1. Digested into glycerol and fatty acids 1. Glycerol may be converted into glucose via gluconeogenesis, or it may change into DHAP then PGAL for glycolysis 2. Fatty acids are transported to the matrix of the mitochondria where they undergo β-oxidation, where they are cleaved, removing acetyl groups 1. These groups combine with coenzyme A to form acetyl-CoA for Krebs 2. Each cleave uses 1 ATP but produces one NADH and one FADH₂, yielding more energy than glucose

Answer 15

When no oxygen is present, Krebs cycle (doesn’t directly rely on oxygen but if no oxygen is present, pyruvate cannot partake in the Krebs cycle) and ETS cannot progress. As a result, pyruvic acid can build up to toxic levels and NAD⁺ cannot be depleted. To solve these problems, pyruvic acid is converted in a safer molecule and cells regenerate NAD⁺ for use in glycolysis again. There are two ways this is done:

Answer 16

**This occurs in animals and some bacteria**. * Pyruvate --\> lactic acid via accepting H⁺ and electrons from NADH, freeing up NAD⁺ allowing for the repetition of glycolysis. During vigorous exercise, muscle cells use up oxygen faster than it can be supplied, resulting in lots of lactic acid production, causing cramps. Slowing down will allow aerobic respiration to resume, and the useless lactic acid is then transported to the liver where it is converted back to pyruvate.

Answer 17

**This occurs in yeast**. * Pyruvate releases CO₂ --\> acetaldehyde --\> ethanol via accepting H⁺ and electrons from NADH, freeing up NAD⁺ allowing for the repetition of glycolysis. Used in the alcohol industry.

Answer 18

Replenish NAD+

Answer 19

Proton motive force