Biology Unit Three - Energy Mrs. Pearson’s First Semester Biology *For those watching by recording, watch for questions on the slides throughout the presentation. Email me the answers to the questions within two days of the lesson being presented in order to receive credit for watching the recording.

Biology Olympics Break it Down! Today’s word is “chemosynthesis” Chemo means… Synthesis means…

Biology Olympics Chemosynthesis is the use of chemicals by an organism to generate usable energy

Biology USA

KEY CONCEPT All cells need chemical energy.

Lesson Objectives Describe the processes and products of photosynthesis.

Pearson’s Perfectly Pleasant Prefixes and Parts Tri – Di – Chemo - Photo – Synthesis Produce Consume

Why do cells need energy Why do cells need energy? What kinds of things do cells need to do that require energy? Organisms get their energy in different ways – why is this a good thing? What would happen if all organisms got their energy in the same way? If all organisms got their energy in the same way, energy would move in a linear fashion eventually being completely changed into an unusable form. Energy cycles through systems being transferred from one area to another. What else do we see in the environment that cycles? What should humans be careful to make sure “cycles” in our interactions with nature?

The chemical energy used for most cell processes is carried by ATP. Molecules in food store chemical energy in their bonds. Starch molecule Glucose molecule **Those watching by recording, include in your email where food molecules store chemical energy

Energy is released when a phosphate group is removed. ATP transfers energy from the breakdown of food molecules to cell functions. Energy is released when a phosphate group is removed. ADP is changed into ATP when a phosphate group is added. phosphate removed

Organisms break down carbon-based molecules to produce ATP. Carbohydrates are the molecules most commonly broken down to make ATP. not stored in large amounts up to 36 ATP from one glucose molecule triphosphate adenosine diphosphate tri=3 di=2

Fats store the most energy. 80 percent of the energy in your body about 146 ATP from a triglyceride Proteins are least likely to be broken down to make ATP. amino acids not usually needed for energy about the same amount of energy as a carbohydrate

A fat by any other name… What two other names did you see for “fats” on the previous slide? Triglycerides Lipids

A few types of organisms do not need sunlight and photosynthesis as a source of energy. Some organisms live in places that never get sunlight. Like where? In chemosynthesis, chemical energy is used to build carbon-based molecules. similar to photosynthesis uses chemical energy instead of light energy Where could this chemical energy be coming from?

KEY CONCEPT The overall process of photosynthesis produces sugars that store chemical energy.

Photosynthetic organisms are producers. Producers make their own source of chemical energy. Name three producers you would find in a grocery store. Plants use photosynthesis and are producers. Photosynthesis captures energy from sunlight to make sugars. **Those watching by recording, include in your email the definition of a producer.

Chlorophyll is a molecule that absorbs light energy. chloroplast leaf cell leaf In plants, chlorophyll is found in organelles called chloroplasts. Why don’t we find chlorophyll in animal cells?

The light-dependent reactions capture energy from sunlight. take place in thylakoids water and sunlight are needed chlorophyll in the thylakoids absorbs energy energy is transferred along thylakoid membrane then to light-independent reactions oxygen is released Water, sunlight and oxygen are found in this part of the process – what are we missing? Carbon dioxide

The light-independent reactions make sugars. take place in stroma needs carbon dioxide from atmosphere use energy to build a sugar in a cycle of chemical reactions

The equation for the overall process is: 6CO2 + 6H2O  C6H12O6 + 6O2 C6H12O6 granum (stack of thylakoids) thylakoid sunlight 1 six-carbon sugar 6H2O 6CO2 6O2 chloroplast 1 2 4 3 energy stroma (fluid outside the thylakoids) **Those watching by recording, include in your email the equation for photosynthesis.

Questions?