ECHS Biology: Photosynthesis

what is energy

the ability to do work

what is work

the act of creating change

what is the first type of energy

potential energy

what is the second type of energy

kinetic energy

what are the four forms of energy

light, heat, electricity, and chemical compounds

what is ATP

one of the principal chemical compounds the cells use to store and release energy

why is ATP useful to cells

basic energy sources for all cells

how is energy being released and stored

by breaking and reforming the bonds between its phosphate groups

how is ATP different from ADP

ADP is partially charged, while ATP is fully charged molecules

what is the first law of thermodynamics state

energy can be transferred from one form to another, but cannot be created or destroyed

where does energy come from

the sun

what is an autotroph

organisms that make their own food/energy

what is an example of an autotroph

plants use the sun’s energy to make food

what is a heterotroph

organisms that obtain their energy from food that they consume

what is an example of a heterotroph

animals; humans, dogs, cats, snakes, mushrooms, insects, ect.

what happens during photosynthesis

plants use light energy to produce food

where does photosynthesis occur

in the leaves or chlorplast

what is pigment

the light reflected, the light something can’t absorb

what is the principle pigment found in plants

chlorophyll

what are plants green

they reflect green light

what is the fluid portion surrounding the thylakoid

stroma

where, within the chloroplast, are pigments found

thylakoids

what is a photosystem

clusters of chlorophyll and proteins; found in the thylakoids and they absorb sunlight

when chlorophyll absorbs light energy, where is it transfered

to electrons

what is an electron carrier molecule

compounds that can accept a pair of high energy electrons and transfer them, along with their energy to another molecule

what is the electron carrier molecule involved in photosynthesis

NADP+

what is it converted to once it receives electrons

NADPH

What is the equation for photosynthesis in words

carbon dioxide + water —sunlight—> sugar + oxygen

what is the photosynthesis equation in symbols

6CO2 + 6H2O — sunlight —> C6H12O6 + 6O2

What is the first part of photosynthesis

light dependent reactions; change light energy into chemical energy; requires light

what is the second part of photosynthesis

light independent reactions (may be known as calvin cycle and dark reaction); produces simple sugars; doesn’t need light; uses the products from the independent light reactions to produce sugars

what is the light dependent cycle

uses energy from sunlight to produce ATP and NADPH

where does the light dependent reaction take place

thylakoid membranes

where do the light dependent reactions reactents

water and light

what are the light dependent reaction products

oxygen gas, NADPH

during the light dependent reaction, water molecules are split which provides what

hydrogen and electrons for the dark reaction

what is the first step in the light dependent reaction

1 sunlight strikes the chlorophyll in the photosystem 2 (PS2) in the plant’s leaves

what is the second step in the light dependent reaction

2 electrons move from the chlorophyll to an electron transport chain (a line of protein)

what is the third step in the light dependent reaction

3 each proteins in the line passes the electron to the next protein

• as the electron moves along, it loses small amounts of energy

• energy lost can be used to form ATP from ADP

• energy that isn’t used for ATP, can be used in the light dependent reactions

what is the fourth step in the light dependent reaction

4 photolysis: the splitting of water molecules into oxygen and hydrogen atoms

what is the fifth step in the light dependent reaction

5 oxygen is given off

what is the sixth step in the light dependent reaction

6 light energy is collected from pigments in the photosystem 1 (PS1) to reenergized electrons which are sent through one or more short electron transport chain; hydrogen hitches a ride on NADP+ (an electron carrier) which carries it to the light independent reaction as NADPH

what is the hydrogen gradient

as water molecules split, H+ ions are pumped into the thylakoid space. this build up of H+ makes the stroma negatively charged in comparison of the thylakoid

what is ATP synthase

protein embedded in membrane and allows it to pass through it

what is the movement of H+ ions across the membrane called during ATP synthase

chemiosmosis

light reaction review:

takes in water; gives off oxygen; send ATP and NADPH to calvin cycle

Explain the light dependent reaction

synthesis part of photosynthesis; no light requires; ATP and NADPH used to produce high energy sugar from carbon dioxide

where does the light dependent reaction take place

stroma

what are the reactants in the light dependent reaction

CO2, ATP, and NADPH

what are the products in the light dependent reaction

sugars, NADP+, and ADP

what is another name for the light dependent reaction

the calvin cycle or the dark reaction

what is the first step in the light dependent reaction

1 6CO2 enters the cycle and combines with other carbon molecules

what is the second step in the light dependent reaction

2 ATP and electrons from NADPH are used to convert carbon molecules into higher energy forms

what is the third step in the light dependent reaction

3 some of the high-energy carbon molecules are used for sugars, lipids, amino acids, and other compunds

what is the fourth step in the light dependent reaction

4 the remaining carbon molecules are recycled for the next cycle

light independent reaction review:

takes the ATP and NADPH from light reaction; takes in CO2; gives off sugar; sends ADP +P and NADP+ back to the light reaction

What is the first factor that affects photosynthesis

1 water (amount and type)

What is the second factor that affects photosynthesis

2 light (color of light, intensity, and distance from light)

What is the third factor that affects photosynthesis

3 carbon dioxide (amount)

What is the fourth factor that affects photosynthesis

4 temperature

what is the first alternative type of photosynthesis

C4: a specialized chemical pathway to capture even very low levels of carbon dioxide; helps minimize water loss through closing the stroma; the organisms include crop plants like corn and sugar cane

what is the second alternative type of photosynthesis

Cam: cacti and succulents; incorporate carbon dioxide with organic acids; water conserving; separate photosynthesis cycles; CO2 only enters at night

What is a calorie

the amount of energy needed to raise the temperature of 1 gram of water, 1 degree celsius

what is a Calorie

a kilocalorie of 1000 calorie (needed to release energy from food)

what is metabolism

all the chemical reactions that take place inside cells, including those that use energy and those that release energy

what do all metabolic reactions depend on

enzymes/cellular respiration

what is the difference between anabolic and catabolic metabolic pathways

anabolic requires energy where are catabolic produces energy

what does the word Glycolysis mean

the splitting of glucose

what is cellular respiration

the process that releases energy from food in the presence of oxygen

what is the glycolysis equation in symbols

6CO2 + C6H12O6 —>6CO2 + 6H2O + energy

what is the glycolysis equation in words

oxygen + glucose —> carbon dioxide + water +energy

why does chemical energy need to be released slowly

otherwise most of the energy would be lost in the form of heat and light

what are the three main stages of cellular respiration

glycolysis, krebs cycle, and electron transport chain

is oxygen requires in glycolysis

no it is anaerobic

what are the reactants in glycolysis

glucose

what are the products in glycolysis

2 pyruvic acids, NADH, ATP

where does glycolysis occur

the cytoplasm

how many ATP are generated in glycolysis

2

what happens during glycolysis

one molecule of glucose is broken in half, producing 2 molecules of pyruvic acid

what is the first step of glycolysis

1 2 ATP’s are put into reaction

what is the second step of glycolysis

2 6 carbon glucose molecules are divided into 2, 3 carbon molecules

what is the third step of glycolysis

3 each 3-carbon molecule loses 2 electrons

what is the fourth step of glycolysis

4 these electrons are carried by the NAD+ to the electron transport chain in the form of NADH

what is the fifth step of glycolysis

5 4 ATP’s are formed

if there is one thing to remember from glycolysis:

it produces 2 pyruvic acid, 2 ATP and 2 NADH

What follows glycolysis if oxygen is absent

fermentation

what follows glycolysis if oxygen is present

kreb’s cycle

what is another name for the krebs cycle

citric acid cycle

is oxygen required in the krebs cycle

yes - aerobic

what are the reactants in the krebs cycle

pyruvic acid

what are the products in the krebs cycle

ATP, CO2, NADH, and FADH2

where does the krebs cycle occur

in the mitochondria

how many ATP are generated in the krebs cycle

2 (and carbon)

what is the first step in the krebs cycle

1 pyruvic acid from glycolysis enter mitochondria

what is the second step in the krebs cycle

2 1 carbon is removed, forming CO2 (now only 2-carbon molecule)

what is the third step in the krebs cycle

3 NAD+ collects electrons forming NADH

what is the fourth step in the krebs cycle

4 coenzyme A joins the 2-carbon, forming acetyl- CO A(remember enzymes help to speed up chemical reactions in our cells)

what is the fifth step in the krebs cycle

5 2-carbon molecules join a 4-carbon molecule (now citric acid)

what is the sixth step in the krebs cycle

6 1 carbon is removed from citric acid as CO2 (now 6-carbon)

what is the seventh step in the krebs cycle

7 NAD+ collect electrons, formign NADH