Test 2: Energy

What are the reactants and products in the reaction that alcohol dehydrogenase catalyzes?

Reactants: Ethanol + ADH → Products: Acetaldehyde

What toxic substance leads to hangover symptoms?

Toxic substance that causes hangover symptoms: Acetaldehyde

What is the original source of all energy on the earth?

The sun

 How would you identify the activation energy on a reaction graph?

The activation energy is the energy needed to start a reaction the energy hill reactants must climb.

What do all reactions need to get them started?

Activation energy 

What do enzymes do in regards to #5 above? What biomolecule makes them?

Enzymes speed up chemical reactions by lowering activation energy.

Most enzymes are proteins.

Biologically speaking, what is metabolism?

Metabolism is all the chemical reactions that happen in a cell. 

What is the role of ATP? What are its three parts?

ATP stores and transfers energy to power cell activities 

Its 3 parts are:

1. Adenine 

2. Ribose 

3. Three phosphate groups 

 Where are the products in a given reaction? (i.e. are they before, after, or on top of the arrow)

After the arrow (→)

Example: Reactants →products

Where is the enzyme in a given reaction? (i.e. are they before, after, or on top of the arrow)

The enzyme is above or below the arrow, because it helps the reaction happen but is not used up.

What part of an enzyme recognizes its substrate? How does it recognize it?

The active site recognizes the substrate.

It recognizes it because the substrate fits the active site in shape, size, polarity, and charge.

How does heating an enzyme-mediated reaction affect the rate? What happens as you gradually warm all the way until it gets very hot?

Heating a reaction with an enzyme will make it go faster until it hits the optimal point. The reaction rate will slow down after that as the enzyme becomes denatured. 

An ATP molecule gives an enzyme one of its high energy phosphates. That enzyme has been _________. (It may have been “activated”, but be more specific.)

Phosphorylated

What is likely to happen when there is a product buildup during a reaction?

The reaction will slow down or stop because the buildup of product can inhibit the enzyme

What happens to the concentration gradient once equilibrium is reached?

The concentration gradient disappears because the solute concentration is equal on both sides. 

Assuming they are following their concentration gradient, how do small, nonpolar molecules cross the membrane?

They cross the membrane by diffusion, moving from high concentration to low concentration.

Water will osmose from a _______tonic solution to a ______tonic solution until both sides are ____tonic.

Hypotonic, Hypertonic, Isotonic

Describe the process of exocytosis.

A vesicle fuses with the cell membrane and releases its contents outside the cell.

What type of transport would a cell use to move molecules from an area of high concentration to low concentration?

Passive transports, no energy needed.

When would a cell use phagocytosis? Osmosis? Simple diffusion? Exocytosis? Active transport?

Phagocytosis: To engulf large particles, like bacteria.

Osmosis: To move water across the membrane.

Simple diffusion: To move small molecules from high to low concentration.

Exocytosis: To move materials out of the cell.

Active transport: To move substances against the concentration gradient using energy.

What do we call the sources of energy we receive from the buried organic material of prehistoric organisms?

We call these energy sources fossil fuels, such as coal, petroleum, and natural gas. They come from the buried remains of ancient organisms.

When did carbon dioxide levels really start rising?

Carbon dioxide levels really started rising in the mid-1800s, when humans began using fossil fuels heavily.

What process occurs in the chloroplast?

Photosynthesis occurs in the chloroplast. It uses light energy to make sugars from carbon dioxide and water.

Specifically, which part of that process occurs in the thylakoid membrane?

The light-dependent reactions occur in the thylakoid membrane. They use light energy to produce ATP and NADPH.

Does a pigment absorb or reflect the color it appears to us?

The color you see is the color it reflects. 

When do accessory pigments typically become visible?

Accessory pigments typically become visible when chlorophyll breaks down, such as during autumn.

What does chlorophyll transmit light energy to?

ChlorophyII transmits light energy to the photosystems.

What is the original source of electrons in the light dependent reaction? Where do they ultimately end up at the end of it?

The original source of electrons is water. The electrons ultimately end up in NADPH.

Where do the products of the light reaction go once they leave the light dependent reaction?

ATP and NADPH go to the light independent reactions Calvin cycle to help make sugars. Oxygen leaves that plant as a waste product.

What molecule is the source of the oxygen gas plants make?

The oxygen gas comes from water when water molecules are split apart.

Where do hydrogen ions flow from and to as they go through ATP synthase in the light dependent reaction?

Hydrogen ions flow from the thylakoid compartment into the stroma through ATP synthase.

 Where do electrons go once they leave the electron transport chain? Where do they go after that?

After the first electron transport chain, the electrons go to Photosystem I. After photosystem I, they enter a second electrons transport chain and eventually are used to form NADPH.

What kind of transport is it when hydrogen ions flow from the matrix of the thylakoid through ATP synthase?

It is passive transport facilitated diffusion because the hydrogen ions move through ATP synthase down their concentration gradient.

Which part of photosynthesis happens in the stroma?

The Calvin Benson cycle happens in the stroma of the chloroplast.

What are the three reactants of the light independent reaction?

Carbon Dioxide (CO2)

ATP

NADPH

Why is oxygen so pr6953one to become a free radical?

Oxygen can easily combine with escaped electrons from the electron transfer chain. This forms reactive free radicals.

What is the first step of aerobic respiration?

Glycolysis is the first step of aerobic respiration. It occurs in the cytoplasm.

What are two differences between the outer and inner membrane of the mitochondrion?

The outer membrane is smooth. The inner membrane is folded and contains proteins for ATP production.

What is the effect of free radicals on a cell?

Free radicals can damage cell molecules such as proteins and DNA.

What is the net yield of ATP from glycolysis?

The net yield is 2 ATP.

What accumulates in the intermembrane space of the mitochondria?

Hydrogen ions accumulate in the intermembrane space.

How do hydrogens in the mitochondrial matrix leave? What two things do they combine with?

They leave through the electron transfer chain. They combine with electrons and oxygen to form water.

Where does aerobic cellular respiration end?

Aerobic respiration ends at the electron transfer chain.

 How do hydrogen ions get from the intermembrane space and into the matrix?

The flow of H+ ions powers ATP synthase.

What type of transport is the process above?

Facilitated diffusion.

What powers ATP synthase?

The flow of H+ ions powers ATP synthase.

What reactant enters the krebs cycle that is further broken down to harness high energy electrons and ATP?

Acetyl-CoA.

Where is the electron transport chain located for cellular respiration?

The inner mitochondrial membrane

Where do the electrons from glucose finally end up at the end of aerobic cellular respiration?

The electrons end up on oxygen and form water.

Where does fermentation take place?

Fermentation takes place in the cytoplasm of the cell.