AP Bio- Matter 7: Matter & Energy Processing.

Matter & Energy Processing

A Reminder:

Things that require matter movement:

• taking in nutrients (food, O2)
• breaking molecules down
• building molecules
• making ATP
• removing waste
• reproduction
• regulation
• all life processes

Energy is Processed NOT "Made"

...Matter is, too!

Any Questions?

Make Sure You Can:

Big Questions:

Explain why cells need to process matter and energy and how they do it.

Explain the relationship between chloroplasts and mitochondria.

Explain the relationship between structure and function in all organelles mentioned in this presentation.

Explain how the organelles in this presentation provide for essential life processes.

Refine your understanding of endosymbiosis in light of the information discussed in this presentation.

What is the relationship between matter and energy?

Why does life require matter?

Why does life require energy?

How do the interactions of cellular components allow the cell to process matter and energy?

The Life of the Cell

Energy Processing

Why do cells need Energy?

Where do cells get energy from?

*There are a few exceptions

Energy: The ability to do work. Stored in chemical bonds.

Meaning: The ability to move matter around.

2 major sources:

• Food
• The Sun*

All cells must do the following things to stay alive:

• Process matter: Molecules need to be acquired, synthesized and digested
• Process energy: In order to process matter, energy must be provided. This energy usually comes from one of two places (where?)
• Process information: The instructions that enable the cell to process matter and energy must be interpreted by the cellular system. Signals from the environment must also be interpreted.

Many cells will also do the following :

• Reproduce: The information that runs the cell must be passed on to new generations of cells.
• Communicate: Cells respond to/direct other cells.

Cells convert incoming energy to forms that they can use using two major organelles:

Mitochondia

Chloroplasts

Sunlight

CO2 & H2O

Cells have systems to do all of these things!

O2 & Sugar

Heat

Energy process: Photosynthesis

From sunlight to Carbohydrates

Energy process: Respiration

From food (glucose) to ATP

ATP = contains easily broken bonds (quick energy usage)

Adenosine TriPhosphate (ATP)

Major Energy/Matter Processors:

Lysosomal diseases:

• often fatal.
• digestive enzyme don't work

Lysosomes

Mitochondria

Almost all eukaryotic cells have mitochondria

The more active the cell, the more mitochondria

Structure:

A sac full of digestive ("hydrolytic") enzymes

Lysosomal "Storage" diseases:

• lysosome picks up molecules but can’t digest them.
• lysosomes fill up, grow larger & larger until disrupts cell & organ function
• more than 40 known diseases

Tay-Sachs disease:

Mitochondria are stained red:

• a recessive genetic disease.
• undigested fat builds up in brain cells
• mental retardation and death at an early age (by 4)

Structure:

• Outer membrane
• Highly folded inner membrane (why?)
• Cristae: folds of the inner membrane
• Matrix: Fluid filled inner cavity. Contains DNA, free ribosomes & enzymes

Function:

• Digestion of large molecules
• Digestion of damaged cell parts
• Apoptosis ("programmed cell death")

Cytosol pH is 7.

Lysosomal enzymes work best at pH 5 (why?)

Other "-somes"

There are all sorts of specialized digestive sacs in cells.

Apoptosis is responsible for the space between your fingers, your nostrils, your eyelids, and generally every hole in your body (that's supposed to be there).

Ex. Peroxisomes

• breakdown fatty acids to sugars
• detoxify cell
• detoxifies alcohol & other poisons
• produce peroxide (H2O2- a dangerous molecule)

See if you can guess which of these 2 white blood cells has gone apoptopic.

Hint: an apoptopic cell breaks apart into vesicles called "blebs". The blebs are absorbed by neighboring cells.

Mitochondria reproduce independently of the cell

Vacuoles

Central vacuoles: in many mature plant cells

• storage
• stockpiling proteins, inorganic ions
• depositing metabolic byproducts
• storing pigments, defensive compounds

Structure:

An membranous sac full of "storage" materials.

Functions:

Food vacuoles: Contain undigested food. Fuse with lysosomes.

Function:

Aerobic cellular respiration

• Digestion ("catabolism") of macromolecules to produce ATP, CO2 and H2O

Can you spot the difference?

Contractile vacuoles: in freshwater protists, pump excess H2O out of cell.

Thank your mitochondria!

Plant-like cell

Animal-like cell

Chloroplasts make plants green (why?)

Chloroplasts

Energy Processing & Evolution

Mitochondria & Chloroplast Similarities:

• both transform energy
• both generate ATP
• both have double membranes
• both are "semi-autonomous" organelles (not part of endomembrane system)
• both move, change shape, divide on their own
• both have small internal ribosomes, circular DNA & make their own protein enzymes

Structure:

• Outer Membrane
• Inner Membrane
• Stroma: liquid inside inner membrane. Contains DNA and Ribosomes & enzymes. Where sugar is made.
• Thylakoids: Membranous sacs inside inner membrane. Where ATP is made. Stacked into "Grana"

How can we explain these facts?

Only plant-like cells have chloroplasts!

Endosymbiosis

But wait, there's more!

Similar patterns of plastid evolution & diversification are seen in algae, too.

Chloroplasts are just one of a group of plant organelles called "plastids" All plastids are the products of endosymbiosis (DNA sequence analysis puts plastid ancestors near modern cyanobacteria)

give flowers and fruit their colors

Function:

Photosynthesis

• Building ("anabolism") of sugar from ATP, CO2 & light. Produces O2 as waste

stores lipids

stores protein

synthesize and store starch