Honors Biology- Unit 3

What happens to energy when bounds are formed?

Energy is being used to make the bound and keep the substances together.

What happens to energy when bounds are broken?

Energy is made

What is the overall function of an enzyme in cellular respiration and photosynthesis? 

The main function is to act like a biological catalyst that accelerates the complex chemical reactions by lowering the activation energy required for them to proceed. 

What are the five factor that affect the rate of a chemical reaction?

temperature, concentration of reactants, surface area of solid reactants, presence of a catalyst, and the nature of the reactants.  

What is metabolism?

All of the chemical reactions within each cell of an organism. It provides energy for life's processes and creates key molecules

What are chemical reactions?

a process where existing chemical bonds break and new ones form, leading to the transformation of initial substances (reactants) into different substances (products) with altered chemical compositions and properties

What is a catabolic reaction?

Breaks down larger molecules into simpler compounds. It is a release of energy which equals exergonic 

What is a anaboloic reaction?

Builds larger molecules to form smaller ones. Requires consuming energy to do it which equals endergonic

What is activation energy?

The amount of energy needed to make a chemical reaction start

What is a reactant (substrate)?

Substances that are changed during a chemical reaction 

What is a product?

Substances that are made by a chemical reaction

What is endothermic?

Absorbs energy in the form of light and heat

What is exothermic?

Releases energy in the form of light or heat.

What is an enzyme?

Mostly proteins that speed up biochemical reactions by lowering the activation energy.

What is a catalyst?

substances that speed up reactions without being permanently altered

What is the active site?

The place where the enzyme meets the substrate

What is denaturation?

enzymes active site gets deformed and losses it specific shape and loss of biological activity. This is caused by environment changes like: extreme changes in pH, temperature, iron strength, and solubility.

What does ATP stand for?

Adenosine Triphosphate

What is the purpose of ATP?

to serve as the universal "energy currency" of the cell, providing the readily usable energy needed for virtually all cellular activities, such as muscle contraction, nerve impulse propagation, and the synthesis of proteins and DNA

Describe the APT-ADP cycle and what is recycled and what is not

The ATP-ADP cycle is the constant interconversion of adenosine triphosphate (ATP) and adenosine diphosphate (ADP) to provide usable energy for cells. When ATP is used, it breaks into ADP and an inorganic phosphate group (Pi), releasing energy for cellular work. The ADP and Pi are then recycled when new energy, derived from nutrients via cellular respiration, reattaches them to form ATP again. The energy released from ATP hydrolysis is not recycled but is used to power cellular activities, while the inorganic phosphate is recycled within the cycle

Explain what the energy is used for when a phosphate is removed, and where that energy initially comes from.

When a phosphate is removed from ATP (adenosine triphosphate) through a process called hydrolysis, the released energy is used to power cellular processes like muscle contraction, active transport, and biochemical reactions. The energy initially comes from the breakdown of food molecules, such as glucose, during cellular respiration

Summarize why the overall process of breaking down ATP is considered an exothermic process, while the overall process of forming ATP is considered an endothermic process.

Breaking down ATP is exothermic because the repulsion of its negative phosphate groups and the formation of stable, lower-energy products (ADP and Pi) results in a net release of usable energy. In contrast, forming ATP is endothermic, requiring an input of energy from sources like cellular respiration to force ADP and Pi together against this repulsion, creating a higher-energy, less stable molecule to store energy.  

What is ATP?

the principal energy currency used by cells to power biological processes

What is chemiosmosis

the process in cells where energy from an ion gradient, most often a proton (H+) gradient, is used to create ATP, the cell's primary energy currency

What is photosynthesis?

The process used by plants, algae, and some bacteria to convert light energy into chemical energy to produce food for themselves and oxygen as a byproduct. 

What is the stroma?

The fluid-filled space around the thylakoids that is the sight for the light-independent reactions.

What is Chlorophyll?

The green pigment in plant, algae, and bacteria that is essential for photosynthesis

What is the grana?

A stack of disc-shaped thykloids membranes inside the chloroplasts, which is where the light-dependent reaction occurs.

What is a autotroph?

A organism that produces its own food from organic substances like carbon dioxide and water using an external energy source

What is a chloroplast?  

A organelle found in plant cells that is responsible for photosynthesis

What is a chemical equation?

A equation that has the reactants on the left side and the products on the right side separated by an arrow

What are reactants?

The starting substances that are consumed and changed into something else.

What is a product?

Any substance or molecule that is formed as a result of a chemical reaction

What is ATP?

The primary energy in all cells that is used to power most cellular activities

What is ADP?

The molecule that acts as a rechargeable energy currency in cells, it is formed when a phosphate group is removed from ATP

What is the light-dependent reaction?

The first stage of photosynethesis that takes places the grana, it takes pigment form the thykloid. This process uses light energy to split water molecules, release energy and produce the energy carrying molecules like ATP and NADPH. 

What is the light-independent reaction? 

The second stage of photosynethesis, also known as the Calvin cycle. The reaction occurs in the stroma and uses the energy from the light-dependant reaction (ATP and NADPH) to turn carbon dioxide into glucose and creates oxygen as a byproduct.

What is the photosystem?

A complex of proteins and pigments, like chlorophyll, that captures the light during photosynthesis

What are electron carriers?

Proteins and molecules that accept and donate high-energy electrons like ATP and NADPH, moving them from one photosystem to the next in a series called the electron transport chain

What is chemosynthesis? 

A biological process by which organisms form organic compounds (food) from simple carbon molecules using energy derived from the oxidation of inorganic chemicals rather than sunlight

What is stomata?

Microscopic pores, typically on the underside of leaves, they are surrounded by two special guard cells. They are a critical part of plant life as they regulate the exchange of gases.

what is photorespersation?

A metabolic pathway in plants that occurs when the enzyme RuBisCO binds to oxygen and not carbon dioxide. This process consumes energy and releases previously fixed carbon, making it less efficient than photosynthesis 

What is the chemical formula for photosynthesis and what are the products and reactants?

6O2 + 6H2O ——> C6H12O6 + 6O2

Left is the reactants and the right is the products

Summarize where all energy on Earth comes from and the overall process it goes through to be in a usable form of ATP for consumers like us.

The energy originates from the sun, which is captured by plants through photosynthesis to create glucose. The energy is then transferred up the food chain when organisms eat plants or other animals. Finally, through cellular respiration, this energy is converted to ATP, the reusable energy currency of cells, for processes like growth and movement.

Why are plants green?

Because of the Chlorophyll

Describe the light-dependent reactions in photosynthesis

Purpose: To convert light energy into chemical energy to make ATP and NADPH 

Reactants: water, ADP, and NADP

Products: Oxygen, ATP, NADPH

Products for the next stage: ATP and NADPH

Location: In the thykloid or granum inside the chloroplast

Describe the light-independant reactions in photosynthesis

Purpose: To use the ATP and NADPH produced from the light-dependent reaction to convert carbon dioxide into glucose and other sugars.

Reactants: carbon dioxide, ATP, and NADPH

Products: Glucose, ADP, and NADP

Products for the next stage: ADP and NADP

Location: In the stroma in the chloroplasts

What is another name for the light-independent reaction?

The Calvin Cycle

What is the difference between ATP and ADP? Which energy molecule provides more energy?

ATP has one more phosphate group then ADP and ATP has more energy

What is the name of the pigment that absorbs the sunlight in the light-dependent reactions?

The chlorophyll

What are the three differences between plant cells and animal cells?

Plant cells have a cell wall which animals don’t, plants have chloroplasts for photosynthesis which animals cells don’t have, and plant cells have a central vacuole to store food and water which animal cells lack

When does photosynthesis occur?

During the day when the plant has access to light

What is aerobic respiration?

It happens when there is a presence of oxygen and the cells can therefore perform the citrus acid cycle and the electron transport chain to produce a large amount energy (ATP)

What is anaerobic respiration?

There is a lack of sufficient oxygen so the cells are unable to perform aerobic respiration. Instead they perform anaerobic respiration when in low oxygen environments, some electron adapters use nitrate or sulfate or fermentation instead of oxygen

What is cellular respiration?

The process that converts the chemical energy in glucose into ATP to be used for energy 

What is the inner membrane?

The highly folded barrier that separates the mitochondria matrix from the inter membrane space, playing a critical role in cellular respiration 

What is the matrix?

The innermost compartment of the mitochondria, a dense, gel-like fluid enclosed by the inner membrane 

What is glucose?

A simple sugar that serves as the primary source of energy for the blood cells

What is glycolysis? What are the reactants and products? Where does it occur? What moves on to the next stage?

A metabolic pathway that splits a glucose molecule in half, producing a small amount of ATP and NADPH. The reactants are glucose, 2ADP, and 2 NAD, and 2 inorganic phosphates. The products are 2 pyruvate, 2 ATP, 2 NADH, and 2 H2O. It occurs in the cytoplasm. Pyruvate and NADH move on to the next stage.

What is the Krebs cycle/ Citrus Acid cycle? What are the reactants and products? Where does it occur? What products move onto the next stage?

A series of chemical reactions in the mitochondria that complete the breakdown of glucose, fatty acids, and protein to make energy. The reactants are NADH and Pyruvate and the products are ATP, NADH, and FADH2. It occurs in the mitochondria matrix. The products that move onto the next stage are NADH and FADH2.

What is the electron transport chain?

The final stage of aerobic respiration where a series of protein complexes in the inner mitochondria membrane that converts the energy from electron carriers like NADPH and FADH2 into a protein gradient, which drives the synthesis of ATP 

What is alcoholic fermentation?

It is performed by yeast during an anaerobic reaction to convert glucose into ethanol and carbon dioxide.

What is lactic acid fermentation?

Happens in the muscles during an anaerobic reaction to converting glucose into lactic acid to make ATP and continue the process of glycolysis. 

What is the mitochondria?

A organelle within a eukaryotic cell, often called the powerhouse of the cell because it generates the most of the cells energy in the form of ATP

What is the equation for cellular respiration?

C6H12O6 + 6O2 ——> 6CO2 + 6H2O + ATP

What are the reactants and products in cellular respiration?

Reactants- C6H12O6 and 6O2

Products- 6CO2 and 6H2O and ATP

What is required in aerobic respiration, what is produced, and where does it happen?

Requires oxygen and glucose. It happens in the mitochondria. It produces mainly ATP and some Carbon Dioxide and water. Produces 32-38 ATP per glucose molecule

What is required in anaerobic respiration, what is produced, and where does it happen?

Requires glucose as the starting molecule as well as a lack of oxygen and some other enzyme to complete glycolysis, and needs alternative electron adapters like sulfate, nitrate, and fumarate in place of oxygen. Occurs in the cytoplasm of the cell. The products are lactic acid in humans and ethanol and carbon dioxide in organisms like yeast. Produced 2 ATP per glucose molecule 

What is the overall goal of cellular respiration and why is it important for humans?

The overall goal is to turn food, like glucose, into energy in the form of ATP. It is necessary because it gives humans the energy to carry out all bodily functions.

What is the electron transport chain? What are the reactants and the products? Where does it occur? What will be released as a product?

A series of protein complexes in the inner mitorcondria membrane that converts the energy from electrons into a electrochemical gradient ro produce ATP. The reactants are NADH and FADH2 and oxygen and the products are ATP, water, and NAD and FAD to regenerate. It occurs in the inner mitochondria membrane. The products that are released are ATP and water.