Biology - Chapter 7-8: Photosynthesis
Stroma
the matrix within the chloroplast that surrounds the grana and within which the light-independent reactions of photosynthesis occur
Chemical energy
the energy stored in the bonds between atoms and molecules in compounds
Terminal electron acceptor
the final molecule to accept electrons in an electron transport chain
Calvin cycle
the light-independent reactions of photosynthesis that convert carbon dioxide to glucose
passive transport
the movement of materials across the cell membrane via diffusion without using cellular energy
3rd phosphate group, adenosine diphosphate (ADP)
Most of the energy stored in the ATP molecule is found in the bond joining the ___ __________ _____ to the rest of the molecule. When this bond is broken, energy is released resulting in _________ ___________ (___), an inorganic phosphate group, and energy to do work
isotonic, hypertonic, and hypotonic
There are three types of solutions:
protein pumps
To actively transport small molecules across the cell membrane, special molecular machines, called _______ _____, are necessary
bulk processes
To transport large molecules in active transportation, ____ _________ are used
passive transport and active transport
Transport across the cell membrane can be divided into two categories:
can damage the photosystems and enzymes involved in photosynthesis
What can be damaged in plants at high temperatures?
Spatially separate carbon dioxide uptake
What do C4 plants do?
separate carbon dioxide uptake and fixation by time
What do CAM plants do?
grasses
C4 plants include:
Summary of light-dependent reactions
(1) Light energy raises the energy of electrons in photosystem II, followed by electron transport. Water is split, and oxygen is formed. (2) Light energy raises electron energies in photosystem I, and electron transport produces NADPH. (3) ATP is made by combining ADP and inorganic phosphate (Pi) H+ ions pass through ATP synthase.
adding a new phosphate group with its associated bond energy
ADP can be recycled back into ATP by doing what?
cellular molecular machines
ATP is able to power ________ _________ ________ by doing many different chemical reactions
endocytosis and exocytosis
Bulk transport can be divided into two mechanisms:
flowering plants, cacti, orchids, and succulents
CAM plants include what?
join an inorganic phosphate to ADP, producing ATP
Chlorophyll absorbs light energy which is used to do what?
positive charge, negative charge
During ATP synthesis, H+ ions collect in the lumen from the splitting of water and some H+ were pumped into the lumen using energy from electrons in electron transport which creates a ________ ______ in the lumen and a ________ ______ in the stroma creating potential energy
lumen, stroma
During ATP synthesis, hydrogen ions enter ATP synthase on the _____ side which provides energy to form ATP in the ______
carbohydrates, lipids, and proteins
Energy stored in _____________, ______, ___ ________ is all converted to ATP for cellular processes
Atmosphere carbon dioxdie enter the cycle and a CO2 molecule is added to a high-energy 5-carbon compound (RuBP), turning it into a 6-carbon molecule which then splits to form two 3-carbon compounded (PGA)
Explain carbon fixation
They open their stomata at night to take in carbon dioxide and store it. During the day, the stomata close, and the stored carbon dioxide is released
How do CAM plants function?
2
How many photosystems are along the thylakoid membrane?
can cross the membrane
If something is in high concentration inside the cell relative to the outside, it will diffuse out, but only if it ___ _____ ___ ________
6, 1, 18, 12
It takes _ molecules of CO2 to form two 3-carbon sugars which can be combined into _ 6-carbon glucose molecule. This consumes __ ATP and __ NADPH.
electromagnetic radiation
Light energy is a form of what?
Across the thylakoid membranes of the chloroplast
Light-dependent reactions occur where?
light-dependent reactions & light-independent reactions
Photosynthesis can be divided into 2 stages-
absorb: red and blue light reflect: green light
Pigments involved with photosynthesis absorb and reflect what light?
carbon dioxide
Plants use what to make sugars during the second stage of photosynthesis?
stroma
The ______ plays an important role in the second part of photosynthesis, when sugars are made
homeostasis
The cell membrane is essential to maintaining ___________, or balance, in a cell
outer, inner, and thylakoid
The chloroplast consists of 3 membranes-_____, _____, ___ _________-each one inside the next
electron transport chain
The high-energy electron from photosystem II is passed to photosystem I along an ________ _________ _____ embedded in the thylakoid membrane
oxygen gas
The light-dependent reactions are responsible for the ______ ___ released in photosynthesis which comes from splitting water
photosystem II
The light-dependent reactions begin with the capture of light energy by the ___________ __ antenna complex in the thylakoid membrane
enzymes
The reactions in photosynthesis occur rapidly because of what?
NADP+ oxygen
The terminal electron acceptor is _____ in photosynthesis and ______ in cellular respiration
capture and store light energy
The thylakoid membranes hold the molecular machinery, in the form of pigments, that do what?
C4 plants and CAM plants
There are 2 major variations to the Calvin cycle that are found in a variety of plants to solve problems of dry conditions-
diffusion, facilitated diffusion, and osmosis
There are three types of passive transport:
-G3P can be exported from the chloroplast to the cytoplasm where it is converted into the monosaccharides fructose and glucose and eventually into the disaccharide sucrose -Some G3P remains in the chloroplast which turns into starch which happens when photosynthesis produces more sugars than needed
What else can G3P be used for? It usually makes glucose
water, carbon dioxide, temperature, and light
What factors affect photosynthesis?
the rate of photosynthesis increases however there's a limit that the rate won't exceed
What happens as light intensity increases?
High: damage photosystems Low: photosynthetic rates decline
What happens during high and low light levels?
The remaining five 3-carbon molecules (G3P) undergo a series of reactions that consume ATP to produce 3 of the 5-carbon molecules (RuBP) which is the starting molecule
What happens during the recycling phase of the calvin cycle?
the 3-carbon molecules (PGA) are made more energetic by contributing a high-energy bond from ATP and by transferring the high-energy electrons from NADPH resulting in a 3-carbon sugar with a phosphate bonded to it (G3P) One out of 6 of the G3P molecules can be removed from the Calvin cycle to be built into glucose
What happens during the reduction stage?
may turn their leaves away from direct sunlight
What happens to plants in high temperatures?
it may wilt, collapse, and die
What happens when a plant doesn't have enough water?
the energy currency of the cell
What is ATP often called?
contains a nitrogenous base (adenine), bonded to a 5-carbon sugar (ribose), bonded to 3 phosphate groups
What is ATP's structure?
carbon-fixation phase
What is the first phase of the Calvin cycle?
regeneration of RuBP or recycling
What is the last phase of the Calvin cycle?
6CO2 (carbon dioxide) + 6H2O (water) + light → C6H12O6 (glucose) + 6O2 (oxygen)
What is the photosynthesis equation?
sugar production (reduction)
What is the second phase of the calvin cycle?
photosystem I
When an electron reaches ___________ _, it is re-energized by the absorption of light by another chlorophyll molecule and 2 high-energy electrons are transferred to NADP+ to form NADPH in the stroma
dependent: during the day when sunlight is present independent: occur during the day or night as long as the products of the light-dependent reactions are available
When do light independent and dependent reactions occur?
a high-energy electron
When light energy is captured by photosystem II, it raises the energy level of an electron creating what?
water and oxygen evaporate out and carbon dioxide diffuses in
When stomata open what goes in and out?
outside the thylakoids in the stroma of the chloroplast
Where do light-independent reactions occur?
photosystem
Within the thylakoid membrane, chlorophyll & other pigment molecules are arranged in large groups called antenna complexes which belong to a group of embedded membrane proteins called a __________
ATP energy
___ ______ is used by protein pumps to transport molecules across a cell membrane
cold, heat
____ slows chemical reactions, while ____ can speed them up
active transport
a cell transport mechanism that uses energy to move materials against a concentration gradient from low to high concentration
exocytosis
a form of cell transport where the cell releases material into the surrounding environment by fusing vesicle membranes with the plasma membrane
Light energy
a form of electromagnetic energy; visible light occupies the range of wavelengths between 400 and 700 nm which is the color spectrum of a rainbow
Photosystem
a group of molecules, including pigments that are embedded in the thylakoid membrane for capturing light energy
ATP synthase
a large enzyme that spans the membrane of thylakoids and mitochondria; involved in the synthesis of ATP from ADP and inorganic phosphate
Pigment
a light-absorbing molecule
Thylakoids
a membrane-bound structure inside chloroplasts composed of disk-shaped vesicles stacked into grana inside of which is a fluid-filled space called the lumen
ATP
a molecule that stores and releases energy in a wide variety of cellular processes and reactions
Chlorophyll
a plant pigment found in chloroplasts involved in capturing light energy for photosynthesis
C4 plants
a plant that fixes carbon dioxide into four-carbon compounds to input into the Calvin cycle of photosynthesis
Enzyme
a protein catalyst that speeds up chemical reactions by reducing the energy needed for a reaction to take place
Cellular respiration
a series of enzyme-catalyzed chemical reactions in cells that converts chemical energy (glucose) into a form the cell can use
electron transport chain
a series of molecules embedded in a membrane that can accept electrons and pass them to neighboring molecules
Diffusion
a type of passive transport by which particles move from an area of higher concentration to an area of lower concentration
Osmosis
a type of passive transport involving the diffusion of water across a membrane
Facilitated diffusion
a type of passive transport where the passage of substances across the cell membrane is assisted by carrier proteins or protein channels
NADPH
an electron carrier, or doner, formed from NADP+, H+, and two high-energy electrons
Chloroplasts
an organelle found in plants and some algae that contain pigments that capture light for photosynthesis
hypotonic
describes a solution with less dissolved solute and a higher concentration of water than a solution on the other side of a membrane
hypertonic
describes a solution with more dissolved solute and lower concentration of water than a solution on the other side of a membrane
isotonic
describes a solution with the same concentration of dissolved solute and water as a solution on the other side of a membrane
Stomata
pores on the underside of a leaf surface that can open or close to control transpiration and gas exchange
Grana (singular granum)
structures in chloroplasts composed of stacks of thylakoids
ATP-ADP cycle
the biochemical cycle that converts adenosine diphosphate (ADP) and inorganic phosphate to adenosine triphosphate (ATP)
The calvin cycle
the calvin cycle
endocytosis
the cellular process of taking in material through a plasma membrane by forming a vesicle around the substance
Light-dependent reactions
the photosynthetic reactions carried out in the chloroplast that generate ATP and NADPH
Light-independent reactions
the photosynthetic reactions carried out in the stroma of chloroplasts in which energy from ATP and NADPH is used to build organic compounds
Photosynthesis
the process in which light energy is captured by autotrophs and used to provide energy for chemical reactions that produce energy-rich molecules and oxygen from carbon dioxide and water
Carbon fixation
the process of taking inorganic carbon in the form of carbon dioxide and incorporating it into organic molecules