Second Quarter 2020 - 2021 School Year- Welcome!

The new links for first Zoom meeting is posted on the high school's page and under the announcement section in Canvas. After which a new link will be posted in Google Classroom and in Canvas.

Some of the Vitamins Needed for Cellular Respiration

You will list the vitamins, state the source, the functions and the deficiency symptoms. The vitamins and minerals to be examined are those that are directly related to the cellular respiration: Vitamin B1 - Thiamine Vitamin B 2 - Riboflavin Vitamin B3 - Niacin Vitamin B6 Pantothenic acid Chromium Iron

Chapter 6: How Cells Harvest Chemical Energy

 Cellular Respiration

The Mitochondrion:

Final Exam Information

 The information is posted in Google classroom.  The folder to upload your work is also available.

Molecular Movements

 Video link for Cell transport

Water Poisoning: Analogy based on the true story of Hold you wee for a Wii

The Plasma Membrane

 Pages 48 and 49 of the packet have been uploaded to Google Classroom.

Enzyme Activity Lab.

 Lab will be demonstrated over Zoom. Report is due at the end of the class.

Cofactors and Coenzymes

 Many enzymes require non-protein substances to function. Without them the enzymes would not work efficiently.  There are two types of these enzyme helpers:

 1) Cofactor: inorganic molecules, minerals, usually metal ions. For instance magnesium is important in reactions where a phosphate group is transferred. One example of this is reversible reaction of ATP.
These cofactors can turn enzymes on and off or modify the rate at which enzymes work. Iron is another example.  Iron is an integral part of hemoglobin's ability to transport oxygen,

2) Coenzymes: organic compounds like vitamins. Coenzymes bind to specific site on a protein molecule and provides chemical functions that a protein alone cannot provide.  You body can make the necessary enzymes, but not the necessary minerals and vitamins which must be included in the diet.

Enzymes: The Biological Catalyst

 Remember that enzymes usually end in ase; catalase, sucrase. 

The enormous of biochemical reactions occurring within cells is regulated by enzymes.  Enzymes speed up chemical reactions, as well as control the rate at which reactions occur.  They are globular protein molecules manufactured by each cell.  More than 2000 enzymes have been recognized based on the chemical reactions they catalyze.  All of them are structurally different

An enzyme recognizes a specific molecule called a substrate and binds to it.  Some enzymes are so specific they only act on one substrate, while others can act on a class of substrate.

Enzymes can bring about changes to molecule to which it binds. The change usually involves the forming or breaking of a covalent chemical bond.  Enzymes may split the substrate into two pieces, may add a chemical side group to the molecule, or may simply rearrange the bonds in the substrate.

 

 Enzymes lower the activation energy by 1) providing a medium that is more favorable than the surrounding one. 2) By bringing the reactant into close contact. 3) They might add or remove a proton from the substrate , strain the substrate molecule's bond, or even form temporary covalent bond between the substrate and some part of the enzyme itself.

Exergonic and Endergonic Reactions:

 In an exergonic reaction energy is released so the reactants have more energy than the products.  For example: Cellular Respiration.  See equation below.

   

In an endergonic reaction the product has more energy than the reactant. For example; Photosynthesis. See the equation below.

The Working Cell

First Law of Thermodynamic: 

The law of Conservation of Energy.

Energy cannot be created or destroyed, but can be changed from one form to another.

Second Law of Thermodynamics

The Law of Entropy: the measure of the amount of disorder or randomness in a system
When energy is transformed from one form to another, there is a loss of usable energy as heat.

 

 

Reviewed How to Write a Lab Report

The  review was necessary to prevent having a repeat of the errors encountered in the Nutrient Lab.  You can again review the Lab Write-up Format posted in a separate tab on this blog.

The folder for Chapter 4 uploads is available on Google classroom.

The test will be on Monday, October 12, 2020

PowerPoint Uploaded to Google Classroom

 Chapter 4 Packet is due on Friday.  

The Study Guide for the chapter 4 multiple choice test is listed in Google Classroom and the school home work page.

 

 

 

 

 

A Tour of the Cell

Video links: An Overview of the Cell Structure

Amoeba Sisters: Introduction to the Cell

Here is the link to the video clip shown in 3rd period.

Inside a Human Cell

Today's class we continued with the functions of the organelles.  

The Animal Cell

 

 

 "Seeing is believing." The invention of the microscope made it possible to see cells and millions of tiny living organisms that are everywhere.

In 1665 Robert Hook used an early microscope to look at a thin slice of cork, the dead cells of oak bark. What he saw looked like rooms, which he called cells.  The microscope was developed from eyeglass markers ideas in the late 1500 who realized that using several glass lenses magnified things.

The Light Microscope allows light to pass through a specimen and uses two lenses to form an image.  Light waves are scattered as they pass through material.  Therefore light microscopes can magnify up to about 1000 times.

Electron Microscopes use beams of electrons focused my magnetic fields. These offer higher resolutions than light microscope.  These are used to only examine non-living cells and tissues.  The samples are chemically preserved so that they can be examined in a vacuum. The electrons are placed in a vacuum to prevent them from being scattered. 

 

Click on the link below to see how electron microscopes work:

How Electron Microscopes Work