Unit 3: Cell Energy

Terms in this set (87)

The ability to do work or a property of objects which can be transferred or converted into different forms

Energy in motion

Potential Energy

An object's potential to do work; stored energy

Law of Conservation of Energy

Energy cannot be created nor destroyed, it can only be converted or transformed into other types of energy

Examples of Conversions of Energy

Ex. in photosynthesis, light energy is transformed into chemical potential energy in the form of glucose

A molecule that transfers energy from the breakdown (catabolism) of food (cell energy) called adenosine triphosphate with 3 phosphate bonds

What ATP is used for

Cell processes like building molecules and moving materials by active transport

Energy is stored in the _____________ in ATP

In the bond of the third phosphate group because it is unstable/easily broken

Most important energy sources for heterotrophs

1) Carbohydrates (most common)
2) Lipids (most energy yield)
3) Proteins (not usually broken down)

Structure of ATP

Importance of Phosphate groups

The phosphate groups store energy in their bonds, most of it in their third phosphate group

A type of lower-energy molecule called adenosine diphosphate with 2 phosphate groups; it can be turned back into ATP

Cycle of ADP--->ATP

Provides energy to add phosphate back onto ADP

Energy from breakdown of carbon-based molecules with the help of enzymes

Where all chemical energy in carbon-based molecules (food) is stored

Amount of energy needed to raise the temp. of 1 gram of water 1 degree celsius

Amount of energy need to raise the temp. of 1 kilogram (1,000 grams) of water 1 degree celsius

Producers of their own food (self feeders)

Consumers of autotrophs and other heterotrophs as source of food

Process where some organisms use chemical energy rather than light energy to make carbon-based molecules of energy/sugars. It is found below light penetration (like deep sea) in hydrothermal vents where hydrogen sulfide used

Photosynthesis definition

Process of taking in sunlight to transform into sugars that store chemical potential energy

Equation for Photosynthesis

6CO2+6H2O--->C6H12O6 + 6O2

Electromagnetic Spectrum

Describes all electromagnetic rays

Location of Visible Light

Small section in middle of electromagnetic spectrum

Colors of white (visible) light

ROY G. BIV (red, orange, yellow, green, blue, indigo, violet)

Where photosynthesis occurs within leaf cells

Chlorophyll a & b

Absorbs mostly red and blue wavelengths
Reflects green pigment to the eyes, absorbs every color except green

Type of pigment found in leaves that absorbs sunlight

Accessory Pigments

Additional pigments found in plants that appear when chlorophyll dissipates during certain months

Stack of thylakoids (membrane-enclosed compartments) where light-dependent reactions take place

Membrane-enclosed compartments in grana where light dependent reaction/photosystems I & II takes place

Fluid that contains grana, 2nd stage of photosynthesis occurs here (Calvin Cycle/light-independent reaction)

Light-Dependent Reactions: Reactants and Products

Reactants: Sunlight, H2O, O2
Products: NADPH, ATP, O2

Light-Dependent Reactions STEP 1

Takes place in grand across membrane of thylakoids where chlorophyll absorbs sunlight in photosystem and water molecules are broken down into hydrogen ions, electrons and oxygen gas, which O2 is released as a waste

Light-Dependent Reactions STEP 2

Energy from electrons is used to make ATP and NADPH to go onto later stages of photosynthesis in ETC in photosystem II (TWO B4 ONE). Electrons make NADPH because it adds electrons to NADP+ (like ADP-->ATP)

Light-Dependent Reactions STEP 3

In photosystem I, chlorophyll absorbs more sunlight and charges electrons. Hydrogen ions (H+) are sent to ETC after being built up in thylakoid membrane with energy from electrons

Light-Dependent Reactions STEP 4

Now, H+ is very concentrated inside thylakoid membrane. H+ (Hydrogen ions) flow through ATP Synthase and makes ATP.

Products of Light-Dependent Reactions

ATP, NADH, and O2. Oxygen is given off as a waste product.

Specialized protein (group of enzymes) found along ETC in chloroplasts that takes in Hydrogen ions (H+) and then uses the energy to attach a phosphate group to ADP, which creates ATP

Light-Independent Reaction STEP 1

Also known as the CALVIN CYCLE. The energy molecules from ETC (NADPH & ATP) are used to power the Calvin Cycle. It occurs in the STROMA and needs CO2 molecules to function.

Light-Independent Reaction STEP 2

CO2 molecules are added to 5-carbon molecules to form 6-carbon molecules. Then, the 6-carbon molecules split into 3-carbon molecules with more energy.

Light-Independent Reaction STEP 3

Two 3-carbon molecules with high energy bond together to form one 6-carbon SUGAR. The cycle then repeats.

Products of Light-Independent Reactions

Glucose, NADP+, and ADP
NADP+ and ADP will go back to LD reactions

Chemical Formula of Light-Independent Reactions

CO2---->C6H12O6

Functions of Photosynthesis

Plants produce food for themselves and heterotrophs, and animals use oxygen produced by photosynthesis in cellular respiration.

Reasons why Photosynthesis and Cellular Respiration are like mirror images

Their chemical reactions are reverse as well as the sequence between the cycles and ETC in each. The O2 released from photosynthesis helps with cellular respiration. CO2 from cellular respiration helps with photosynthesis.

Main component of plant mass

Carbon dioxide to create polysaccharides in plant

Starch and Cellulose are examples of __________________.

Stored polysaccharides in plants used for plant growth and development.

How Photosynthesis helps regulate Earth's atmosphere

Increased CO2 traps heat, and plants are growing faster due to more CO2. This helps to remove some CO2 from the Earth's atmosphere as O2 is a byproduct of photosynthesis.

Powerhouse of plants, major site of food production (photosynthetic organ)

Epidermis of Leaf

2 tough layers on outer leaf (lower and upper epidermis) which secretes cuticle

Cuticle of Leaf

Waxy substance from epidermis of leaf that protects leaf from insects, bacteria, and other pests on outer surface of leaf

Leaf Guard Cells

Among the epidermal cells. Sausage-shaped cells that forms a pore called the stoma (plural is stomata).

Formed by pore in guard cells. Gases enter and exit through the stoma.

How gases enter leaf

Stoma uses active transport to put potassium ions in the guard cells to swell the cell and provide a pore for gases to enter and be released. HYPOTONIC (swells)

How gases exit leaf

Potassium ions are removed by diffusion and is returned to isotonic state to close pore. HYPERTONIC (closes)

Palisade Mesophyll in Leaf

Layer in leaf that is below epidermal layer of leaf chloroplasts and absorbs a major portion of the light energy for FOOD PRODUCTION used by the leaf.

Spongy Mesophyll in Leaf

Layer in leaf that has many spaces between cells to facilitate the circulation of air and the EXCHANGE OF GASES and is in the interior of leaf

Supports the leaf, filled with vessels that transport food, water, and minerals to plant like a highway.

Cellular Respiration definition

The process of making ATP by breaking down sugars and other carbon-based molecules and is an aerobic process that takes place in the mitochondria

Cell's powerhouse

Cellular Respiration Equation

C6H12O6 + 2O6--->6CO2 + 6H2O

Total # ATP in Cellular Respiration

36 ATP molecules total

Starting process of cellular respiration that means "glucose breaking" where oxygen is not needed yet (anaerobic) in the cytoplasm. 6 carbon glucose broken into two 3-carbon molecules of pyruvate as well as 2 ATP molecules to carry energy for the next process.

Carbon Dioxide's relationship to Glycolysis

Waste Product of Glycolysis

Starting step of Cellular Respiration in mitochondria where pyruvate is taken in from glycolysis and broken down for high-energy electrons that are used to recharge NADP+ to NADPH which moves to ETC. As well, another electron carrier FADH2 is made for ETC. CO2 given off as a waste product.

Products of 1 broken-down molecule of Pyruvate

3 molecules of CO2 that are given off as waste, 1 molecule of ATP, 4 molecules of NADH, 1 molecule of FADH2.

# of PYRUVATE from GLYCOLYSIS

2 PYRUVATE MOLECULES

Electron Transport Chain (ETC) STEP 1

Takes place within inner membrane of mitochondria. Energy is transferred along the chain. Oxygen enters the process and picks up electrons (like the reverse of ETC in photosynthesis) and hydrogen to make H2O. Enzymes required for process. 32 ATP produced here!

Electron Transport Chain (ETC) STEP 2

Hydrogen ions that were stripped from the electron carrying molecules like NADH, FADH2, and ATP are transported across mitochondria membrane. ADP is changed to ATP when H+ flow through ATP Synthase.

Importance of O2 in ETC

Electrons traveling on the ETC are grabbed by the Oxygen molecules and are bonded to Hydrogen to make Water as a waste product

Process that lets glycolysis continue to make 2 ATP molecules when oxygen is unavailable (ex. when running). It is an anaerobic process. NAD+ recycled to glycolysis.

Lactic Acid Fermentation

Occurs in MUSCLE cells. Glycolysis splits glucose into 2 pyruvate molecules. NADH (from broken down pyruvate) and Pyruvate enter fermentation because a build up of NADH can stop glycolysis. Energy from NADH converts pyruvate into lactic acid and NADH-->NAD+

Alcoholic Fermentation

Cheese, bread, yogurt all products. Glycolysis splits glucose and products to enter fermentation. Pyruvate broken down to alcohol instead of lactic acid with NADH. CO2 is waste product. NADH--->NAD+ and is recycled again.

# of minutes glycogen is used

# of seconds cells rely on lactic acid fermentation

Glycogen stored in _______________

Mostly liver and sometimes muscles

Glycogen, fermentation

Long-term energy

Cellular Respiration

Three factors that affect photosynthesis

Light, Temperature, Carbon Dioxide

Graph of Carbon Dioxide Affecting Photosynthesis

Graph of Temperature Affecting Photosynthesis

Graph of Light Affecting Photosynthesis

Why the Leaf Disks floated when exposed to light in the lab

The leaf chloroplasts were photosynthesizing and producing Oxygen, a waste product of photosynthesis. This got trapped in the spongy mesophyll layer of the leaf and caused the disks to float due to buoyancy.

Dependent Variable

Responding Variable; found on the y-axis

Independent Variable

Manipulated Variable; found on the x-axis

Temperatures on Earth because when things heat up, they tend to expand and move

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