bio104 test 2

golgi apparatus

- sort, modify, repackage, ship

cytoskeleton

-contraction, tracts for movement, support shape, anchor

osmosis

-high to low concentration of water -diffusion of water

The main constituents of the Plasma membrane are A. carbohydrates and lipids b. proteins and phospholipids c. fats and carbohydrates d. fatty acids and nucleic acids

b

as glycolysis and the citric acid cycle are completed the carbons in glucose are incorporated into a. water b. carbon dioxide c.ATP d. Glycogen e. pyruvate

b

enzymes speed of chemical reactions by_________ a. heating cells b. binding to substrates and placing stress on their bonds c.changing the shape of the cell d. supplying energy to the substrate

b

most of the energy in an ATP molecule is released ________ a. during cellular respiration b. when terminal phosphate group is hydrolyzed c. in the form of new nucleotides D. when it is transferred to NADH

b

what results if the solute concentration is higher outside the cell? a. osmosis will cause water to move into the cell b. osmosis will cause water to move out of the cell c.osmosis will not cause any water to move d.osmosis will cause the cell to burst

b

which of the following statements is correct? a. women require more calories per day than men? b. a heavier person uses more calories than a thin person while exercising c.a persons metabolic rate will not change d.genetics does not play a role in metabolic rates

b

anaerobic respiration_______ a. generates proteins for muscles to use b. occurs in yeast cells only c. does not use oxygen as the final electron acceptor d. utilizes glycolysis, the citric acid cycle, and the electron transport cycle

c

carbon dioxide functions as a green house gas by? a. interfering with waters ability to absorb heat b.increasing the random molecular motions of oxygen c. allowing radiation from the sun to reach earth and absorbing the reradiated heat. d. splitting into carbon and oxygen and increasing the rate of cellular respiration

c

which of the following is a false statement about photosynthesis? a. during the calvin cycle, electrons and ATP from the light reactions are combined with atmospheric carbon dioxide to produce sugars b. the enzymes of the calvin cycle are located in the chloroplasts stroma c. oxygen produced during the calvin cycle is released into the atmosphere d. sunlight drives photosynthesis by boosting electrons found in chlorophyll to a higher energy level e. electrons released when sunlight strikes chlorophyll are replaced by electron from water

c

which of the following is a false statement regarding enzymes? A. enzymes are proteins that speed up metabolic reactions b. enzymes have specific substrates c. enzymes supply ATP to their substrates d. an enzyme may be used many times

c

what are the reactants and products of photosynthesis?

carbon dioxide and water

active transport across a biological membrane requires _________________ and moves a substance _____________ its concentration gradient a.energy and proteins...down b.energy...down c.proteins....down d. energy and proteins ....against e.proteins ...against

d

cellular respiration involves a. the aerobic metabolism of sugars in the mitochondria by a process called glycolysis b. an electron transport chain that releases carbon dioxide c. the synthesis of ATP, which is driven by the rushing of proteins through an ATP synthase d. electron carriers that bring electrons to the citric acid cycle e. the production of water during the citric cycle

d

select the true statement regarding metabolism in plant and animal cells a. plant and animal cells both perform photosynthesis and aerobic respiration b. animal cells perform aerobic respiration only, and plant cells perform photosynthesis only c. plant cells perform aerobic respiration only, and animal cells perform photosynthesis only d. plant cells perform cells perform cellular respiration and photosynthesis, and animal cells perform aerobic respiration only

d

stomata on a plants surface a.prevent oxygen from escaping b. produce water as a result of photosynthesis c. cannot be regulated by the plant d. allow carbon dioxide uptake into leaves e. are found in stacks called thylakoids

d

water has a high-heat-absorbing capacity because a. the suns rays penetrate to the bottom of bodies of water, mainly heating the bottom surface b. the strong covalent bonds that hold individual water molecules together require large inputs of heat to break c. it has the ability to dissolve many heat-resistant solutes d. initial energy inputs are first used to break hydrogen bonds between water molecules and only after these are broken, to raise the temperature e. all of the above are true

d

what would happen if activation energy barriers didn't exist? a. substrates would not bind properly to enzymes b. chemical reactions in the body would never occur c. enzyme function would not be affected d. metabolic reactions would proceed even if their products were not needed

d

which of the following cannot freely pass through a cell membrane without going through a protein chanel ? a. oxygen b. carbon dioxide c. water d. calcium ion

d

what would happen if activation energy barriers did not exist? a. substrates would not bind properly to enzymes b. chemical reaction in the body would never occur c. the boys metabolism would decrease to the point where food molecules couldn't be broken down d. all chemical reactions in the body would proceed whether they were needed or not

d.

an electron transport chain ______________ a. is located in the matrix of the mitochondrion b. has the electronegative carbon dioxide at its base c. is a series of nucleotides located at the inner mitochondrial membrane d. is a series of enzymes located in the inter membrane space e. moves electrons from protein to protein and moves protons from the matrix into the inter membrane space

e

the burning of fossil fuels_______ a. releases carbon dioxide to the atmosphere b.primarily occurs as a result of human activity c. is contributing to global warming d. is possible thanks to photosynthesis that occurred millions of years ago e. all of the above are correct

e

what is found in animal but not plant cells? A. golgi apparatus b. mitochondria c. central vacuole d. ER e. centrioles

e

which of the following forms of the membrane transport require specific membrane proteins? a. diffusion b. exocytosis c. facilitated diffusion d. active transport e. facilitated diffusion and active transport

e

what is the active site?

enzymes decrease activation energy by binding to their substrate and placing stress on its chemical bonds, decreasing the amount of initial energy required to break the bonds. the region of the enzyme where the substrate binds is called the enzymes active site

what is meant by metabolism?

metabolism includes all the chemical reactions that occur in cells to build up or break down macromolecules

passive transport

movement of molecules without energy (diffusion, facilitated diffusion, osmosis) - high to low concentration

ribosomes

protein synthesis

Describe the 3 stages of cellular respiration -Where in the cell does each stage occur?

stage 1: glycolysis (occurs outside the mitochondria) stage 2: the citric acid cycle (inside the mitochondrion) stage 3: electron transport and ATP synthesis (the inner mitochondrial membrane????)

what is substrate?

the chemicals that are metabolized by an enzyme-catalyzed reaction are called the enzymes substrate

a cell possesses DNA, a plasma membrane and mitochondria. it could not be a. a bacterium b. a cell from a mouse c. an oak tree d. a bacterium or a plant cell e. an animal cell or bacterium

a

what results if the solute concentration is higher inside the cell? a. osmosis will cause water to move into the cell b. osmosis will cause water to move out of the cell c. osmosis will not cause any water to move d. osmosis will cause the cell to shrivel and die

a

which human activity generates the most carbon dioxide? a.driving b.cooking c. bathing d. using aerosol sprays

a

which of the following does not occur during the light reactions of photosynthesis ? a. oxygen is split, releasing water b. electrons from chlorophyll are added to an electron transport chain c. an electron transport chain drives the synthesis of ATP for use by the calvin cycle D.NADPH is produced and will carry electrons to the calvin cycle e. oxygen is produced when water is split

a

which of the following statements are incorrect ? a.enzymes raise the activation energy of a reaction b. enzymes speed up the rate of a reaction c.substrates bind to an enzymes active site d. enzymes change shape when they bind to a substrate

a

how do reactions get started?

all metabolic reactions are regulated by proteins called enzymes that speed up or catalyze the rate of biological reactions

a substance moving across a membrane against a concentration gradient is moving by a. passive transport b. osmosis c. facilitated diffusion d. active transport e. diffusion

d

photorespiration occurs __________________ a. under hot and dry conditions b. when oxygen is incorporated in the first step of the calvin cycle c. when carbon dioxide levels are high inside the plant d. A and B are correct e. A,B, and C, are correct

d

Describe the ATP cycle. What is its significance?

- ATP -> ADP + P + energy ATP + P + energy = ATP

nucleus

- DNA + proteins = chromosomes -nucleolus: site of ribosome production -hold genetic material

Distinguish between anorexia and bulimia.

- anorexia (self starvation) -bulimia (Eating large amount of food but then purging to not allowing the nutrients to turn into fat)

lysosomes

- digestion, housekeeping, protection (immune ) -lysosomal storage disease

active transport

- energy, proteins - against concentration gradient low to high

simple diffusion

- have to be small lipid, soluble -ex, gases -high concentration to low (down the concentration gradient)

What are health issues associated with weight (both high and low weight)?

- if your BMI is below 18.5 you are at risk for anorexia -25-29 overweight

What is the relationship between enzymes and some diseases

- lactose intolerance -PKU; phenylketonuria - mutation in gene for enzyme phenylalanine hydroxyls -result: build up of phenyl -> brain damage

What factors affect a person's basal metabolic rate?

- many factors influence BMR such as exercise habits, biological sex, and genetics.

What is a person's metabolic rate? Basal metabolic rate?

- metabolic rate: is a measure of his or her energy use. this rate changes according to the person's activity level. -basal metabolic rate: represents the amount of energy use of a wakeful person

facilitated diffusion

- not lipid soluble - protein -no energy involved -hydrophylic / charged

effects of global warming

- rise in sea levels -melting of glaciers -loss of habitat for temperature-sensitive species -more severe storms -nasa site -epa

what is the role of cellular respiration?

- series of metabolic reactions that converts the energy stored in chemical bonds of food into energy that cells can use, while releasing waste products. -energy is stored in the electrons of chemical bonds, and when bonds are broken in a multistage process, atp is produced.

Describe Body Mass Index (BMI). How is it calculated? How is BMI information used? What are the issues?

-a value calculated by using your height and weight as an estimate of weight-related illness and death. - BMI = weight (lbs) X 700/ height (in)^2 - this method is not as accurate as it should be, studies show that as many as 1 in 4 people may be misclassified by BMI tables because this measurement provides no means to distinguish between lean muscle mass and body fat. for example, an athlete with a lot of muscle mass will weigh more than a similar-sized person with a lot of fat because muscle is more dense than fat

Describe the structure of ATP. Why is it considered an energy intermediate?

-atp is a nucleotide triphosphate. the nucleotide found in atp contains a sugar and the nitrogenous base adenine - the energy stored in the chemical bonds of food can be released and stored in the bonds of ATP. cells use ATP to power energy-requiring processes -breaking the terminal phosphate bond of ATP releases energy that can be used to perform cellular work and produces ADP plus a phosphate

what is the overall equation for cellular respiration?

-c6h1206 + 602 -> 6 co2 + 6 h20 + energy - series of reactions -

Stage 1: glycolysis

-cytosol - glucose -> pyruvic acid -anaerobic -2 ATP are produced -no 02 - to harvest energy, the 6 carbon glucose molecule is broken down into 3-carbon pyretic acid molecules -occurs outside mitochondria -does not require oxygen -after an initial input of energy, produces a net total of 2 ATP

what is the relationship between activation energy (energy of activation) and enzymes?

-energy barrier prevents molecules from breaking down spontaneously (the energy of activation) -the energy required to start the metabolic reaction serves as a barrier to catalysis and is called the activation energy. if not for the activations barrier, all of the chemical reactions in cells would occur relentlessly, whether the products of the reactions were needed or not. because most metabolic reactions need to surpass the activation energy barrier before proceeding, they can be regulated by enzymes. in other words, a given chemical reaction will occur when the correct enzyme is present. ex. the bike up the hill

mitochondria

-energy processing -found in both animal and plant cells -hold electron transport train

chloroplasts

-energy processing photosynthesis

what are enzymes

-enzymes are proteins -enzymes are catalysts : increase rate of chemical reactions -how? lower the activation energy -enzymes are proteins that catalyze specific cellular reactions. the substrate binds to the enzymes active site and is converted to product. -

how do enzymes work?

-enzymes are selective/specific -a specific enzymes catalyzes each cellular reaction -determines which chemical reaction occur in a cell -substrate fits into active site to break chemical bonds, molecules must absorb energy from their surroundings, often by absorbing heat. this is why heating chemical reactants will speed up a reaction. however heating cells to an excessively high temperature can damage or kill them, in part bc the proteins begin to break down at high temperatures. enzymes do not need heat to catalyze the boys chemical reactions, so they break chemical bonds without damaging or killing cells. - by eliminating the heat energy required to start a chemical reaction, enzymes allow the breakdown of chemical bonds to occur more quickly.

stage 3: electron transport and ATP synthesis

-inner mitochondrial membrane -02 required -h20 produced - electrons harvested during the citric acid cycle are now carried by NADH to the final stage in cellular respiration. the electron transport chain is a series of proteins embedded in the inner mitochondrial membrane that functions as a sort of conveyer belt for electrons, moving them from one protein to another. -the electrons dropped off by NADH molecules generated during glycolysis and the citric acid cycle, move towards the bottom of the electron transport chain toward the matrix of the mitochondrion, where they combine with oxygen to produce water.

stage 2: the citric acid cycle

-mitochondrial matrix -co2 produced -after glycolysis, the pyretic acid is decarboxylated (loses a carbon dioxide molecule), and the 2- carbon fragment that is left is further metabolized inside the mitochondria. -this fragment is then enters the citric acid cycle, a series of enzyme catalyzed reactions that take place in the matrix of the mitochondrion. here the original glucose molecule is further broken down, more of its electrons are harvested and the remaining carbons are released as carbon dioxide

How do nutrients get into our cells?

-nutrients from small intestine to cells -nutrients must get across the plasma membrane - plasma membrane: (phospholipid layer/ selectively permeable)

centrioles

-only animal cells -chromosome movement

cell wall

-plant cells -prokaryotic -strong, porous,flexible -protect and support

what is the relationship between structure and function?

-things that destruct the structure can disrupt how it functions - when the enzyme changes shape, it binds to the substrate more tightly, making it easier to break the substrate's chemical bonds - the enzyme helps convert the substrate to a reaction product and then resumes its original shape so that it can perform the reaction again - each enzyme catalyzes a particular reaction- a property called specificity. -the specificity of an enzyme is the result of its shape and the shape of its active site -different enzymes have unique shapes because they are composed of amino acids in varying sequences.

water crosses cell membranes _____________ a. by active transport b. through protein pores called aquaporins c. against its concentration gradient d. in plant cells but not in animal cells

B

a cell that is placed in salty water will_______________ a. take sodium and chloride ions by diffusion b. move water out of the cell by active transport c. use facilitated diffusion to break apart the sodium and chloride ions d. lose water to the outside of the cell via osmosis

D