Biochemical Pathways: Scientific Method to Respiration

Scientific Method

Systematic approach to investigate observations.

Research Question

Idea to be investigated in an experiment.

Hypothesis

Prediction of the experiment's outcome.

Experiment

Procedure to test the hypothesis.

Independent Variable

Factor changed to observe effects.

Dependent Variable

Factor measured in response to changes.

Controlled Variables

Factors kept constant for valid results.

Denaturation

Loss of enzyme structure, rendering it inactive. Caused by pH levels being innacurate or temperatures being too high.

Enzyme

Protein that accelerates chemical reactions.

Catalyst

Substance that increases reaction rate without consumption.

Substrate

Reactant that binds to an enzyme's active site.

Active Site

Region on enzyme where substrate binds.

Enzyme-Substrate Complex

Temporary structure formed during enzyme action.

Catabolic Reaction

Breakdown of larger molecules into smaller ones.

Anabolic Reaction

Synthesis of larger molecules from smaller ones.

Optimum pH

pH level where enzyme activity is highest. If pH level drops above or below this, can cause denaturation.

Photosynthesis

Process converting light energy into glucose.

Stages of Photosynthesis

Light dependant and light independant (calvin cycle)

Autotrophs

Organisms that produce their own food.

Chloroplasts

Organelles where photosynthesis occurs in plants.

Thylakoid Discs

Membranes in chloroplasts for light-dependent reactions.

Light dependent stage

First stage of photosynthesis. Occurs in the thylakoid membranes of the chloroplasts. Uses energy to split hydrogen and oxygen and to trap light energy into ATP.

Calvin Cycle

Light-independent phase of photosynthesis in stroma. Carbon and Oxygen from carbon dioxide, fixed into glucose using hydrogen and light energy from phase 1.

Aerobic Cellular Respiration

The process by which cells use oxygen to obtain usable energy from an energy source. Produces 30-32 ATP.

Stages of Aerobic Respiration

glycolysis, krebs cycle, electron transport chain.

Glycolysis

First stage of cellular respiration in cytoplasm. Glucose split into two pyruvate molecules via a series of chemical reactions. Net yield of 2 ATP, electrons collected for transportation to electron transport chain.

Pyruvate Molecules

Molecules involved in lots of chemical reactions

Krebs Cycle

Second stage in mitochondria producing ATP and CO2.

Pyruvate molecules from previous section diffuse into matrix of the mitochondria. 8 chemical reactions occur, making up the Krebs Cycle. 2 ATP and carbon dioxide created. Main purpose to collect electrons to transfer to electron transfer chain.

Matrix of the Mitochondria

Innermost section of the organelle Mitochondria

Electron Transport Chain

Final stage generating ATP using electrons. The chain is a series of proteins located on the membranes of the mitochondrial cristae. Electrons from previous 2 stages flow between membrane proteins supplying energy for 26-28 ATP to be made. Buildup of electrons at end of the chain is removed by oxygen, combing with hydrogen to make water.

Mitochondrial Cristae

Many folds within inner part of Mitochondria, increases surface area for chemical reactions.

ATP

Main energy currency of the cell. Stands for Adenosine Tri Phosphate.

Net Yield of ATP

Total ATP produced after each respiration stage.

Photosynthesis Equation

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

Energy Storage Molecule

Molecule that stores energy for cellular functions.

What happens when the energy in ATP is used?

One of the phosphate molecules (Tri-Phosphate) is released, turning the molecule into ADP (di-phosphate) and Pi. Pi stands for inorganic phosphate, and is the molecule that was released.