Cell Transport And Metabolism

Question 1

Differentiate between active transport and passive transport.

Answer 1

Passive transport id the movement of materials across a cell membrane without using its own energy (with the concentration gradient). Active transport is the movement of substances across a cell membrane requiring the cell to use its own energy (against the concentration gradient).

Question 2

Differentiate between phagocytosis and pinocytosis.

Answer 2

Phagocytosis is the process which cells engulf solid particles. Pinocytosis is the process which cells engulf liquid droplets. Both are types of endocytosis.

Question 3

What is the difference between osmosis and diffusion?

Answer 3

Simple diffusion is the random movement of substance from an area of high concentration to low concentration. Osmosis is the diffusion of only water.

Question 4

What is the difference between facilitated diffusion and facilitated transport?

Answer 4

Facilitated diffusion uses special channel protein molecules, it does not use energy and it passive transport. Facilitated transport uses a protein pump, it goes against the concentration gradient and uses ATP.

Question 5

What is the difference between cytolysis and plasmolysis.

Answer 5

Cytolysis is when animal cells burst do to hypotonic solutions. Because they lack cell walls. Animal cells have water removing mechanisms. Plasmolysis is when a plant cell loses water in a hypertonic solution and begin to wilt.

Question 6

What is the difference between endocytosis and exocytosis.

Answer 6

Endocytosis is transport of large molecules into the cell by engulfing the molecule with pseudopods until it gets enclosed by a vacuole. Exocytosis is when large molecules (waste) are stored in vacuoles and move to the cell membrane expelling contents.

Question 7

What is the difference between autotroph and heterotroph.

Answer 7

Autotrophs are organisms that create there own energy using the sunlight through the process of photosynthesis. Heterotrophs get there energy by eating other organisms, they eat other heterotrophs or autotrophs.

Question 8

What is the difference between NAD and NADP.

Answer 8

NAD is only different from NADP because NAPD has a phosphate and NAD does not. Both are electron and hydrogen carriers, they turn into NADH and NADPH. NAD is used in photosynthesis, while NADPis used in cellular respiration.

Question 9

What is the difference between photolysis and phosphorylation?

Answer 9

Photolysis is the breaking down of h20 molecules. Phosphorylation is the attachment of a phosphorus to a molecule or attaching to ADP to make ATP.

Question 10

Label fluid mosaic model

Answer 10

.

Question 11

If salt is dissolved in water what is the solvent and solute?

Answer 11

Solute is the salt
The solvent is the water

Question 12

Define tonicity and be able to use terms isotonic, hypertonic, and hypotonic.

Answer 12

Toni city is The ability of an extracellular solution to make water move into or out of a cell by osmosis.
Isotonic is when there is a equilibrium reached in the cell and the concentrations are the same. Hypertonic is when the solute concentration is higher outside the cell, therefore water leaves the cell to even it out. Hypotonic solution is when the solute concentration is higher inside the cell, therefore the water from outside the cell goes inward.

Question 13

What is energy?

Answer 13

Energy is the capacity of doing work or causing change. It cannot be destroyed or created, only transferred from one form to another.

Question 14

In what form is energy stored in all living organisms.

Answer 14

Cells store sugar molecules as glycogen in animals and starch in plants; both plants and animals also use fats extensively as a food store.

Question 15

What is the significance of the ATP/ADP cycle? How does it work?

Answer 15

If a cell needs to spend energy to accomplish a task, the ATP molecule splits off one of its three phosphates, becoming ADP. The energy released by the ATP must be released in small amounts as particles are passed from 1 acceptée molecule to another.

Question 16

What is a electron transport chain? Why are they important to living things?

Answer 16

A electron transport chain is a series of proteins which are charged by electrons and used to form a electrochemical gradient. This gradient is then used to produce ATP by bonding a phosphorus with ADP.

Question 17

What is a photosystem? Where is it found.

Answer 17

A photosystem is found in the thylakoid membrane. It is where the electron transport chain takes place. Photosystem 2 is the photosystem that comes first in the chain. After the electrons pass down the first chain they get re-energized by the sun and passed down a second, shorter electron chain (photosystem 1). As The electrons pass down the chains they produce energy to turn ADP into ATP.

Question 18

What are the two main stages of photosynthesis?

Answer 18

Light dependent reactions
Light independent reactions

Question 19

What happens in light dependent reactions of photosynthesis? Where does this take place and what is the purpose?

Answer 19

Light dependent reactions takes place in the thylakoid membrane of the chloroplast. The purpose is to produce ATP and harvest h+ ions to use in the light independent reactions. A) The process starts by chlorophyll absorbing photons from the sunlight, causing it to release two high energy electrons. These two high energy electrons pass down a electron transport chain (photosystem 2) releasing NRG which is used to turn ADP into ATP with help from the enzyme protein synthase. The same electrons are then re-energized at the base of the chain by the sunlight. They are then passed down another smaller transport chain (photosystem 1) releasing more energy which is used to turn more ADP into ATP.
B: harvesting hydrogen ions)
Solar energy splits water into H+ ions, a O atom and 2 electrons. The 2 electrons go to the chlorophyll to replace the 2 electrons lost. The H+ ions get picked up by NADP, forming NADPH which is used in light independent reactions to make glucose. The oxygen is given off as a byproduct in the form of O2 gas.

Question 20

What happens in light independent reactions of photosynthesis? Where does it occurs and what is it’s purpose?

Answer 20

It occurs in the stroma (gel like substance in chloroplast). The purpose is to build carbohydrates molecules using the light dependent reactions. It involves using ATP to join carbon dioxide molecules with hydrogen ions to make carbohydrates. It starts by CO2 molecules enter the chloroplast. Energy from ATP joins 3 CO2 molecules together with help from RuBisCO, forming PGA molecules. ATP energy is used to join PGA molecules with H+ ions donated by NADPH to form PGAL. The NADP and ADP are recycled to the light dependent phase. PGAL can be used as is or used to from complex carbohydrates.

Question 21

What is the general formula for photosynthesis?

Answer 21

Chlorophyll and solar NRG
6H2O + 6CO2 ——> C6 H12 O6 + 6O2

Question 22

What factors affect the rate of photosynthesis?

Answer 22

-light intensity
-carbon dioxide concentration
-temperature
-H2O intensity

Question 23

What is cellular respiration? Where does it occur?

Answer 23

Cellular respiration is the process by which the mitochondria of the cells of living organisms break down glucose to make ATP.
=convert NRG stored in glucose to a form the cell can use

Question 24

What are the 3 stages of aerobic respiration?

Answer 24

• glycolysis
• krebs cycle (citric acid cycle)
• electron transport system

Question 25

What happens in glycolysis?where does it occur? What is its purpose?

Answer 25

Glycolysis occurs in the cytoplasm of the cell. The purpose is to split 3 carbon molecules into to be processed by the mitochondria. It does not require oxygen. It starts from a glucose molecule splitting into two 3 carbon molecules of PGAL, using 2 ATP molecules. Each PGAL molecule is converted into pyruvate by removing a H+ ion and electrons energy is released in this process (creates 2 ATP per pyruvate). The H+ ions and e- are picked up by the carrier molecule NAD which becomes NADH. The two pyruvate and NADH molecules are carried over to the next stages. NET TOTALS: C6 H12 O6 produces: 2 pyruvate 2 NADH 4 ATP (-2 invested) = 2 ATP

Question 26

What happens in Krebs cycle? Where does it occur and what is it’s purpose.

Answer 26

Krebs cycle occurs in the matrix (inside of mitochondria). The purpose is to break down pyruvate to harvest H+ ions and e- to put through the ETC (electron transport chain). It starts from a complex set of chemical equations that convert each pyruvate into Acetyl-CoA and then broken apart. H+ ions picked up by the carrier molecules Nad and Fad forming NADH and FADH2 which will be used in the production of ATP. Carbon is joined with the atmosphereic oxygen and given off as a byproduct in the form of CO2 (exhaled). The energy releases from this process releases 1 ATP per pyruvate. NET TOTALS 2 ATP 6 NADH 2 FADH2 4 CO2

Question 27

What happens in the electron transport system (electron transport chain)?

Answer 27

The electron transport system occurs in the cristae (inner folds of mitochondria). It’s purpose is to produce ATP. It starts by all of the NADH AND FADH2 from glycolysis and Krebs cycle getting stripped of the H+ ions and e- and put into the Electron Transport System (requires 2 ATP invested). These ions and electrons are sent down the ETC releasing NRG to create ATP. The hydrogen ions and electrons join with oxygen to form H2O which is exhaled. NET RESULTS 6 H2O (exhaled) 10 NADH produce 30 ATP 2 FADH produce 4 ATP = 34 ATP (-2 invested)= Net 32 ATP

Question 28

What is the general equation for cellular respiration?

Answer 28

C6 H12 O6 + O6—> 6CO2+6H2O+ATP

Question 29

What are the two types of cellular respiration? What are the differences between them? Which is superior, why?

Answer 29

Aerobic respiration: requires oxygen results in complete breakdown of glucose Anaerobic respiration: does not require oxygen, incomplete decomposition of glucose Aerobic is superior because it produces 36 ATP total, while anaerobic only produces 4 ATP.

Question 30

What is anaerobic respiration?

Answer 30

Also called incomplete cellular respiration, anaerobic respiration does not require oxygen to make ATP. Comes after glycolysis but in the absence of O2, pyruvate is converted into more stable products.

Question 31

What are the two types of anaerobic respiration and what happens in each?

Answer 31

Alcohol fermentation: it is used by yeast. Because there is no O2 present the pyruvate is rearranged forming ethanol and releasing CO2. (Animals do not use this) NET RESULTS 2 ATP CO2 Éthanol Lactate fermentation: used by anaerobic bacteria and muscle. Lack of O2 causes pyruvate to lactic acid and CO2 is released. Bacteria is formed. A lack of oxygen during strenuous exercise causes lactic acid build up in muscles, resulting in muscle cramps and fatigue. NET RESULTS 2 ATP Lactic acid CO2

Question 32

What makes phospholipid molecules suitable as a major component of the plasma membrane?

Answer 32

They have a hydrophilic head which is polar and attracts water. While there tails are hydrophobic which are non polar and repel water, this allowed water to pass through easily. Hydrophilic heads and hydrophobic tails also make it fluid.

Question 33

Explain osmosis in terms of differentially permeable membrane.

Answer 33

The plasma membrane is really picky and only allows some substances to pass through it. Water can easily pass through because of the hydrophilic heads and hydrophobic tails of the membrane.

Question 34

Explain why restaurants soak lettuce in water before serving it.

Answer 34

They do this so water enters the membranes of the cells and the lettuce becomes bigger and crispier, due to hypotonic solution.

Question 35

Explain the significance of the atp and adp cycle write a chemical equation showing this reaction.

Answer 35

ADP + Phosphate + NRG= ATP ATP splitting = ADP + Phosphate+ NRG This is significant because it shows us how atp produces its energy and how it can easily recharge with the help of NRG and a phosphate atom.

Question 36

What is a electron transport chain, use a analogy to represent this.

Answer 36

Electron transport systems/chains is when NRG of electrons is released in small amounts as particles (hydrogen) pass from 1 accepter molecule from another to from a electrochemical NRG gradient, which it then passes through ATP synthèse where ATP is formed.

Question 37

Why is the sun the ultimate energy source of all life?

Answer 37

The world is made up of heterotrophs and autotrophs. All heterotrophs rely on eating other heterotrophs or eating autotrophs to get energy (glucose). Because of this, autotrophs must produce there own energy because they do not eat other organisms for energy. Autotrophs preform photosynthesis from the sunlight energy, which produces there own energy. For this reason the sun gives energy to all living organisms.

Question 38

What is turgor/ osmotic pressure?

Answer 38

Turgor pressure inside a plant cell pushing outside into the cell wall. When the cell is in a hypotonic solution the cell had a high osmotic/turgor pressure. When placed in a hypertonic solution the cell has a low osmotic/turgor pressure.

Question 39

What are the Factors affecting selective permeability of the plasma membrane.

Answer 39

-particle size -particle solubility -concentration induise of outside the cell -electrical charge -plasma membrane structure

Question 40

What are the functions of glycoproteins embedded in the phospholipid memrane?

Answer 40

-markers so cells can identify each other -receptors for chemical messages -regulators of what enters the cell -transporters carrying specific materials into it out of the cell