Study Exam 2 Flashcards by Shamat Ashera

Diffusion def

a passive process of transport of low-molecular-weight material down its concentration gradient

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Concentration Gradient def

when the concentration of particles is higher in one area than the other

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Passive Transport def

a method of transporting material that does not require energy

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Direct Diffusion def

the substance moves through a semipermeable membrane or in a solution without any help from transport proteins.

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Facilitated diffusion def

a passive movement of molecules across the cell membrane from the region of higher concentration to the region of lower concentration by means of a carrier molecule.

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Osmosis def

Transport of water via aquaporin

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What solute do animals have dissolved in our cells

~0.9

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What will happen when you place an animal cell in a container of 100% distilled water?

Water will move into the cell and the cell will explode because the concentration of water is higher outside the cell than inside, so water moves in; then concentration of water in cell increases; water moving in increases cell volume causing it to explode

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Isotonic def

Healthy balance of water and solutes(1 water leaves, another enters)

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Hypertonic def

More solutes than water

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Hypotonic def

Less solutes in the cell than water.

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Active transport def

Active transport proteins pump molecules against their concentration gradients using ATP

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difference between active and passive

Active transport requires ATP and moves against the concentration gradient, Passive transport does not use ATP and moves along the concentration gradient

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Similarities between Active and Passive

both move oxygen, water and nutrients into cells and remove waste products.

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10) Which plasma membrane component can be either found on its surface or embedded in the membrane structure?
a. protein
b. cholesterol
c. carbohydrate
d. phospholipid

a) protein

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11) The tails of the phospholipids of the plasma membrane are composed of _____ and are _______?
a. phosphate groups; hydrophobic
b. fatty acid groups; hydrophilic
c. phosphate groups; hydrophilic
d. fatty acid groups; hydrophobic

d) fatty acid groups; hydrophobic

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12) Water moves via osmosis _________.

a. throughout the cytoplasm
b. from an area with a high concentration of other solutes to a lower one
c. from an area with a low concentration of solutes to an area with a higher one
d. from an area with a low concentration of water to one of higher concentration

c) from an area with a low concentration of solutes to an area with a higher one

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13) The principal force driving movement in diffusion is __________.

a. temperature
b. particle size
c. concentration gradient
d. membrane surface area

c) concentration gradient

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14) Active transport must function continuously because __________.

a. plasma membranes wear out
b. cells must be in constant motion
c. facilitated transport opposes active transport
d. diffusion is constantly moving the solutes in the other direction

D) diffusion is constantly moving the solutes in the other direction

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In the context of cell biology, what do we mean by form follows function? What are at least two examples of this concept?

one can deduce the function of a structure by looking at its form, because the two are matched. Two examples: Bird, fish

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Why is it advantageous for the cell membrane to be fluid in nature?

It has a very bitter taste, which discourages consumption by insects and animals.

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Why does osmosis occur?

When there is a concentration gradient of a solute within a solution, but the membrane does not allow diffusion of the solute.

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Where does the cell get energy for active transport processes?

From ATP produced by its metabolism

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Energy def

the capacity to cause change

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Potential energy def

Energy an object has bc of its location or structure

Kinetic energy def

energy of motion

What do all energy conversions generate?

Heat

Where does all energy come from?

the sun

Heat def

a type of kinetic energy contained in the random motion of atoms and molecules

Metabolism def

the total of all the chemical reactions in an organism

Endergonic rxns def

energy absorbed from the surroundings

Anabolic def

small molecules are built into large ones(energy required)

Exergonic rxns def

energy is released to the surroundings

Catabolic def

Large molecules are broken down into small ones. (energy is released)

Relationship between Photosynthesis and Cell Respiration

Photosynthesis converts carbon dioxide and water into oxygen into oxygen and glucose, Cellular respiration converts water and glucose into water and carbon dioxide

Chemical Reactions:

reactants => Bonds (electrons) rearrange => Products

What does a cell need to spend to create more chemical reactions?

energy

Ea - Activation Energy def

Energy required to get from reactants to transition state

Transition state

the state of a reaction when the molecule is neither a substrate or product

Enzymes def

proteins which speed up chemical reactions

Enzymes work based on

their shape

How do enzymes speed up rxns

Reducing Ea (Activation energy)

Enzyme Inhibitors

molecules that bind to an enzyme and disrupt its function

ATP def

Chemical energy used by all cells

ATP is made of

Gamma phosphate group, Beta phosphate group, Alpha phosphate group, Ribose, Adenine

ATP is replenished by

food

ADP is made up of

2 phosphate groups and 1 Adenosine

ATP is turned into ADP when

energy is released and one phosphate group transfers to another molecule

5) Which of the following is not true about enzymes? a. They are consumed by the reactions they catalyze. b. They are usually made of amino acids. c. They lower the activation energy of chemical reactions. d. Each one is specific to the particular substrate(s) to which it binds.

a) they are consumed by the reactions they catalyze

6) Energy is stored long-term in the bonds of _____ and used short-term to perform work from a(n) _____ molecule. a. ATP : glucose b. an anabolic molecule : catabolic molecule c. glucose : ATP d. a catabolic molecule : anabolic molecule

c) glucose: ATP

7) The energy currency used by cells is _____. a. ATP b. ADP c. AMP d. adenosine

a) ATP

8) The glucose that enters the glycolysis pathway is split into two molecules of _________. a. ATP b. phosphate c. NADH d. pyruvate

d) pyruvate

9) What do the electrons added to NAD+ do? a. They become part of a fermentation pathway. b. They go to another pathway for ATP production. c. They energize the entry of the acetyl group into the citric acid cycle. They are converted into NADP.

a) they become part of a fermentation pathway

10) Chemiosmosis involves a. the movement of electrons across the cell membrane b. the movement of hydrogen atoms across a mitochondrial membrane c. the movement of hydrogen ions across a mitochondrial membrane d. the movement of glucose through the cell membrane

c) the movement of hydrogen ions across a mitochondrial membrane

11) Which of the following fermentation methods can occur in animal skeletal muscles? a. lactic acid fermentation b. alcohol fermentation c. mixed acid fermentation d. propionic fermentation

a) Lactic acid fermentation

We inhale oxygen when we breathe and exhale carbon dioxide. What is the oxygen used for and where does the carbon dioxide come from?

The oxygen turns the glucose into energy and the carbon dioxide is the waste from the reaction.

Goal of cell respiration

to capture energy in the form of ATP

Glycolysis location

cytosol

citric acid cycle location

matrix of mitochondria

electron transport chain location

inside mitochondria

Atp synthase location

inner membrane of mitochondria

Steps of cell respiration

glycolysis, pyruvate oxidation, citric acid cycle, oxidative phosphorylation

Inputs and outputs on glycolysis

Inputs-glucose, 2 atp outputs- 2 pyruvate or pyruvic acid, 4 electrons, NET 2 ATP

Inputs and outputs on citric acid cycle

* Inputs:2 pyruvate (from Glycolysis) * Outputs: 2 acetyl-CoA, 4 ELECTRONS, 2 co2

Inputs and Products of Electron Transport Chain (ETC) and ATP Synthase

* Inputs: NADH, H+, ADP, FADH2, O2 Outputs: NAD+, ATP, FAD, H2O

Location of high H+ concentration

Space between inner and outer membranes

location of low H+ concentration

matrix

ATP synthase def

A spinning turbine that uses H+ ions flowing down their concentration gradient to drive ATP production

Role of Oxygen (O2)

Oxygen is the ETCs final electron acceptor

What would happen to the Citric acid cycle and ETC without O2?

Without O2, NADH builds up and the Citric Acid Cycle and ETC stop

Lactic acid def

Lactic acid fermentation is a metabolic process by which glucose or other six-carbon sugars (also, disaccharides of six-carbon sugars, e.g. sucrose or lactose) are converted into cellular energy and the metabolite lactate, which is lactic acid in solution.

CO2 and ethyl alcohol production in yeast fermentation

In brewing, alcoholic fermentation is the conversion of sugar into carbon dioxide gas (CO2) and ethyl alcohol. This process is carried out by yeast cells using a range of enzymes.

Photosynthesis equation:

6CO2(g) + 6 H2O(0) =sunlight> C6H12O6 + 6O2(g)

What does photosynthesis use to release oxygen and to produce energy-storing sugar molecules?

Solar energy, carbon dioxide, and water

Autotroph def

Makes their own sugars and supplies

Glucose Oxidation equation:

C6H12O6 + 6O2(g) => 6 (O2(g) + 6 H2O (l)

photosynthetic organisms

self feeding organisms

Chloroplasts

Site of photosynthesis in eukaryotes

Inputs and Outputs of Photosynthesis

Inputs: 6 Carbon Dioxide, 6 Water, sunlight Outputs: Glucose, oxygen

Role of the light reactions

Energy from sun (sunlight) is used to make ATP and transfer electrons from light to NADPH

Role of the Calvin cycle

ATP and NADPH from light reactions used to build glucose from CO2

Pigments

Plants use pigments to absorb light

3 stages of Calvin cycle

1- RuBisCO (an enzyme) fixes CO2 into an organic molecule => 2- The organic molecule is reduced (gains e-) => 3- Regenerate RuBP (starts the cycle) to continue cycle

stomata def

Openings in the atmosphere that plants use to exchange gases

what does stomata leak?

water vapor

C4 plants are most efficient at photosynthesis in what climates?

hot, sunny climates

why would stomata close

to keep more water