Chapter 3 - Energy, Chemical Reactions, and Cellular Respiration

How ATP energy is released

-It breaks off a phosphate group, turning into ADP and releases energy

what cells need energy for

-Movement, Digestion, Synthesis, Waste removal, Active transport, Reproduction, Maintaining body temp

two types of respiration

-aerobic, anaerobic

allosteric inhibitors

-don't resemble substrate and bind to allosteric site and changes shape of active site so substrate can't bind

first law of thermodynamics

-energy can neither be created nor destroyed, it can only change form

radiant energy

-energy of electromagnetic waves

kinetic energy

-energy of motion, can be harnessed to do work

chemical bonds

-energy stored in a molecule's chemical bonds

catalase

-enzyme that breaks down hydrogen peroxide into water and oxygen

proteins

-form alpha helix or beta sheets

carbohydrates

-form rings

multienzyme complex

-group of enzymes work in a sequence of reactions

accelerating reaction rate

-increase in enzyme concentration -increase in substrate (up to point of saturation - so much substrate is present that all enzyme molecules are engaged in reaction) -slight increase in temperature (most enzymes function at a narrow range of temperatures, 35°-40°C , because protein conformation is destroyed by high temperatures) -slight increase in temperature (most enzymes function at a narrow range of temperatures, 35°-40°C , because protein conformation is destroyed by high temperatures) -optimal pH (narrow range). pH outside of the optimal range interferes with protein bonding and denatures the protein) - different enzymes have different optimal pH

heat

-kinetic energy of random motion, not available to do work

triglycerides

-look like "E"s

Adenosine triphosphate

-major chemical compound that is used to power cellular activities, smaller quantities of energy

reaction rate

-measure of how quickly a chemical reaction takes place

sound energy

-molecule compression caused by a vibrating object

electric energy

-movement of charged particles

cofactors

-nonprotein molecules or ions required for normal enzyme function, inorganic cofactors attach to a particular enzyme, organic cofactors, also called coenzymes, assist enzymes without attaching saturation; -so much substrate is present that all enzyme molecules are engaged in reaction

mechanical energy

-objects in motion

aerobic respiration

-oxygen is always required. During the process of aerobic respiration, the molecules of food are broken down to obtain energy. It takes place in mitochondria and gives off 36 ATP molecules per each glucose molecule. Another term for this process is "cellular respiration"

denaturation

-process of enzyme, or any protein, changing conformation and losing function

enzymes

-proteins that speed up chemical reactions by lowering activation energy

anaerobic respiration

-respiration occurs without the use of oxygen. It produces less energy in comparison to aerobic respiration: only 2 ATPs are yielded per each glucose molecule. Another term for this process is "fermentation". There are two types of fermentation, alcohol and lactic acid fermentation (based on the products resulting from each process: alcohol or lactic acid)

metabolic pathways

-series of enzymes, one product becomes the next substrate

food molecules

-store large quantities of energy in a stable form over long periods of time

potential energy

-stored energy, energy of position

inhibitors

-substances that bind to enzymes and prevent enzymatic action.

activation energy

-the amount of energy required to break existing chemical bonds and start a chemical reaction

chemical reactions

-the process of breaking chemical bonds in existing molecular structures and forming new ones, atoms are rearranged

Respiration

-when energy from food molecules is transferred into ATP, the process that breaks down organic molecules (like glucose) in order to transfer their energy to ATP molecules which, in their turn, will be used by cells

second law of thermodynamics

-when energy is transformed, some is lost to heat and the amount of usable energy is decreased, entropy

chemical equations

-written summary of changes

carbohydrate glucose

-your body's major fuel molecule

How Enzymes work

1. Enzymes catalyse only those reactions that happen naturally. 2. Enzymes are specific: each enzyme is responsible for only 1 kind of reaction, because they are shaped to work with only a certain substrate that matches enzyme's active site. 3. Enzyme changes its conformation when substrate bonds to its active site. This creates stress on the substrate's bond making them easier to break (induced fit model) 4. Enzymes are not changed by the reaction. They are needed in small quantities, because they are reused.

Competitive inhibitors

resembles substrate and compete for occupation of active site