Biology; Chapter 4- The Energy of Life

An example of an energy-requiring reaction is ______, which uses energy from the sun to produce sugars; an example of an energy-releasing reaction is cellular ____, which releases the energy in sugars.

- photosynthesis - respiration

Organisms transform energy from one form to another. Put the following forms of energy in the order that they are harvested and converted, starting at the top with a form of energy that is no in an organism.

1 sunlight is captured 2 sugars are synthesized in plants and some microbes 3 sugars are broken down to liberate energy that powers cellular activities

Place the following events in the correct order in which they occur in photosystem I, beginning with the first event at the top.

1. Antenna pigments capture a photon of light. 2. Energy is passed to the electrons of the reaction center. 3. Two excited electrons are passed the second electron transport chain. 4. The ejected electrons are replaced with electrons passing down from photosystems ll.

Place the following events in the correct order in which they occur in photosystem II, beginning at the top with the entry of photons into the photosystem.

1. Antenna pigments capture a photon of light. 2. Light energy is transferred to the reaction center. 3. Two electrons carrying potential energy are passed to the electron transport chain.

Place the following events in the correct order in which they occur in the CAM pathway, beginning at the top with the entry of carbon dioxide into the leaf.

1. Carbon dioxide diffuses into the leaf when stomata are open at night. 2. Carbon dioxide is stored as a four-carbon molecule in vacuoles within mesophyll cells. 3. The stored four-carbon molecule is moved from vacuoles to choroplasts of mesophyll cells and carbon dioxide is released. 4. Carbon dioxide enters the Calvin cycle when the stomata are closed during the day.

place the following events in the correct order in which they occur during the first part of the photosynthetic electron transport chain of the light reactions, between photosystem ll and photosystem l. Start with the first event at the top.

1. Light energy is absorbed at photosystem ll, and electrons are ejected from a chlorophyll a molecule. 2. The electrons are shuttled through a series of proteins in the thylakoid 3. The energy lost from the electrons drives the active transport of protons from the stroma into the thylakoid space. 4. The electons arrive at photosystem l.

In the light reactions of photosynthesis, what drives the synthesis of ATP by ATP synthase?

A proton gradient across the thylakoid membrane

Match each oathway letter on the image to the type of plant it represents.

A; C3 Plant B; C4 Plant C; CAM Plant

select all of the following that are products of the calvin cycle

ADP NADP+ Glucose (from PGAL)

The Calvin cycle cannot proceed without the molecules ____ and _______, which are produced by the light reactions of photosynthesis

ATP and NADPH

Select all of the following that describe CAM plants.

Adapted to dry habits conduct the C4 pathway at night 3-4% of plant species

Which of the following are typically or always heterotrophs?

Animal and fungi

In C4 plants, the Calvin cycle takes place within ____ sheath cells, which are not exposed directly to atmospheric oxygen and therefore rubisco binds more often to carbon dioxide, reducing photorespiration.

Bundle

in _________ plants, the light reactions and first carbon fixation reaction occur in mesophyll cells, and the calvin cycle occurs in bundle-sheath cells. this arrangement ensures that rubisco always encounters high ____ concentrations, which reduces photorespiration.

C4; CO2

Select all of the following that occur in C4 plants.

CO2 is first fixed to form a four-carbon molecule. Photorespiration is minimized The calvin cycle takes place in bundle-sheath cells.

Select the names of the two stages of photosynthesis.

Carbon reactions and light reactions

Match the photosynthetic pigments with their correct descriptions. chlorophyll a chlorophyll b carotenoids

Chlorophyll a : most abundant pigment in plants; reflects green wavelengths of light Chlorophyll b: accessory pigment that reflects green wavelengths of light. Cartenoids: accessory pigment that reflect red, orange, and yellow wavelengths of light.

ATP is a nucleotide that stores potential between phosphate groups.

Energy

True or false: Photosynthesis only occurs on land.

False

In the overall reaction of photosynthesis, carbon dioxide and water molecules are converted into oxygen gas and ____, which the plant uses for food.

Glucose

Products of photosynthesis

Glucose (C6H12O6) Oxygen (O2)

In each chloroplast, there are between 10 and 100 _________, which are of stacks of thylakoids.

Grana

How do enzymes speed up biochemical reactions?

Lower the activation energy

Within a plant leaf, most photosnthetic occurs in cells called ________ cells, which are often interspersed with air spaces to maximize gas exchange.

Mesophyll

The second part of the electron transport chain in the light reactions uses electrons to reduce NADP+ and form_________

NADPH

In the CAM pathway, stomata are ____ at night to let CO2 in when water loss is less and are ____ during the day while maintaining a high concentration of carbon dioxide in the chloroplasts.

Open; Closed

Redox reaction occur simultaneously: for every molecule that is reduced gains elections), another molecule is ___ (loses electrons.

Oxidized

Categorize each description into the correct pathway.

Photorespiration; Rubisco binds oxygen and eventually releases carbon dioxide (reverse of carbon fixation). Takes place in C3 plants when stomata are closed and O2 concentration in leaves rises. C3 Pathway; CO2 binds to rubisco to form PGA, the first step in a patheay that fixes carbon as glucose. Takes place in C3 plants when stomata are open and O2 concentrations in leaves are low.

Match the pathway with the correct description

Photorespiration; Oxygen is used by the enzyme rubisco in an energetically wasteful reaction. C3 Pathway; Carbon dioxide is used by the enzyme rubisco to produce PGA C4 photosynthsis; Carbon dioxide is used to produce a four-carbon molecule, and the Calvin cycle takes place in bundle-sheath cells. CAM Photosynthesis; Carbon dioxide is incorporated into a four-carbon molecule at night, and the Calvin cycle takes place during the day in mesophyll cells.

In a photosystem, antenna pigments capture photon energy and funnel it to the ____________ _________________, which consists of a pair of chlorophyll a molecules that actually use the light energy in photosynthetic reactions.

Reaction Center

Plants conduct gas exchange in photosynthesis by bringing in carbon dioxide and releasing oxygen through

Stomata

The openings in the epidermis of a leaf or stem for gas exchange are called

Stomata

Why do photosynthesizers contain accessory pigments in addition to chlorophyll a?

To absorb wavelengths of light that chlorophyll a cannot and extend the range of wavelengths captured

What happens to the glucose produced in photosynthesis

Used as energy for cellular respiration combine with other molecules used to build cellulose of cell walls

The oxygen by-product of photosynthesis is created by the spiltting of _______ molecules to replace the electrons

Water

what is required for simple diffusion?

a concentration gradient

a. Energy-requiring reaction b. Energy-releasing reaction

a. products contain more energy than reactants b. reactants contain more energy that products

Chlorophyll b and carotenoids are examples of

accessory pigments

The ___________ pigments of photosystems pass the captured photon energy to the reaction center.

antenna

Organisms called ____________ , such as this deer, eat the plants to obtain food molecules.

autotrophs

select all of the following essential cellular activities that are conducted by enzymes

breakdown food DNA replication Protein Production

What is the most abundant pigment in plants?

chlorophyll a

The ___________ pigments of photosystems pass the captured photon energy to the reaction center.

chloroplasts

which of the following are examples of potential energy? Select all that apply.

compressed spring ball at the top of a hill chemical energy stored in bonds

A group of proteins in the thylakoid membrane that shuttles electrons between proteins is called

electrons transport chain

no ___ i spent to pass a substance acoss a membrane in a passive transport.

energy

the ability to do work is called ____.

energy

Living organism are able to increase in complexity due to a constant input of ____ from the sun but because the universe as a whole is also deceasing in complexity by a greater amount, the ____ in the universe is always increasing.

energy ; entropy

without _____ many reactions would occur too slowly for an organism to survive

enzymes

according to the laws of thermodynamics, energy transformations overall lead to ____ disorder.

increase

in an isotonic solution, the solute concentration

is equal between two neighboring areas

the energy being used to do work is called ____ energy and is the energy of motion.

kinetic

Within the electromagnetic specturm, visble light provides the energy for photosynthesiss and has a

middle-range wavelength and medium amount of energy.

the process in which a reaction s products inhibit the enzyme that catalyzes the reaction in called

negative feedback

Electromagnetic radiation consists of discrete packets of kinetic energy called ____, which are characterized by a certain wavelength and energy level

photons

The enzyme rubisco adds oxygen instead of carbon dioxide to RuBP in a process called

photorespiration

In a metabolic pathway called __________, plants, algae, and some types of bacteria convert solar energy

photosynthesis

Select all of the following that are photosynthetic organisms.

plants, algae, some microbes, and cyanobacteria & some bacteria

the energy contained in the covalent bonds of molecules is a form of ____, which can be converted to kinetic energy that the cell can use to do work.

potential energy

what type of membrane transport is shown in the picture and lacks a carrier molecule?

simple diffusion

Match the methods of membrane transport with the correct descriptions.

simple diffusion; movement of solutes from high to low concentrate without a transport protein. facilitated diffusion; movement of solutes from high to low concentration with a transport protein osmosis; movement of water from areas of high water concentration (low solute concentration) to areas of low water concentration (high solute concentration) active transport; movement of solutes from low to high concentration with a transport protein

The Calvin cycle is also called

the C3 Pathway

select all of the following that are examples of kinetic energy

the movement of molecules light a rolling cart

The active site is the place on an enzyme where

the substrates bind

Inside a chloroplast, the ___ are pancake-shaped membranes studded with photosynthetic pigments

thylakoids

energy cannot be created or destroyed

true

Place the following events in the correct order in which they occur in the Calvin cycle, beginning at the top with the carbon fixation step:

1. The enzyme rubisco combines carbon dioxide with RuBP to form a 6-carbon unstable molecule. 2. The 6-carbon molecule splits to form PGA. 3. PGA is converted into PGAL. 4. Some PGAL is converted into glucose and other sugars, and some PGAL is converted back to RuBP.

The second stage of photosynthesis is called the ____ reactions, which use ATP and NADPH to reduce carbon dioxide to glucose molecules

Carbon

Reactant of photosynthesis

Carbon dioxide (CO2) Water (H2O)

Select all of the following that occur during the first part of the photosynthetic electron transport chain of the light reactions, from photosystems ll to photosystem l.

Electrons are ejected from chlorophyll a oxygen is produced pigments in the photosystem absorb light energy Protons are pumped into the thylakoid space

Select all of the following that are true about photosynthesis.

Photosynthesis is a reaction that requires energy. Carbon dioxide is reduced Electrons are removed from the oxygen atoms in water.

Within the chloroplast, the gelatinous fluid containing DNA, ribosomes, and enzymes is called

Stroma

Select all the components of a photosystem.

accessory pigments, proteins, chlorophyll pigments, and a reaction center chlorophyll

The region where a substrate reactant binds to an enzyme is called the ____ site.

active

select all of the following that occur during the second part of the photosynthetic electron transport chain of the light reactions, from photosystem l and on.

pigments in the photosystem absorb light energy NADPH is produced Electrons are ejected from chlorophyll a

During the photosynthetic electron transport chain, protons are pumped into the ___________ from the stroma and then pass back to the stroma through ___________ channels, which are enzyme complexes that can use the energy released from the protons to generate ATP.

thylakoid space; ATP synthase