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Biology Unit 1. Chapter 2- The chemical composition of cells. Intracellular fluid The environment within a cell. Internal environment. Some of the major bodily systems are involved in this regulation process: Respiration Digestion Circulation. Plants and Animals.
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Biology Unit 1 Chapter 2- The chemical composition of cells
Intracellular fluid The environment within a cell.
Internal environment • Some of the major bodily systems are involved in this regulation process: • Respiration • Digestion • Circulation Plants and Animals • Regulated so that cells can function at their optimum levels • Aspects regulated: -ion concentration -temperature -pH -Nutrients, water and waste levels and removal What happens when the above aspects are not regulated?
Organic and Inorganic compounds • Compounds are organized into 2 types: • Organic compounds – These are complex chemical compounds which contain Carbon and Hydrogen. • Inorganic compounds- These are all non-organic compounds. e.g. water, oxygen, nitrogen.
Inorganic components Water- most organisms are 70-90% water • Surface tension • Heat capacity • Cohesiveness Oxygen and carbon dioxide • Oxygen is needed for cells to release energy from food molecules • Carbon is the key molecule in organic molecules. Nitrogen • Nitrogen is needed to make proteins. Minerals • Are needed for the structural part of cells, the body and in enzymes and vitamins
Organic molecules Carbohydrates • Important source of energy • Made of carbon, hydrogen and oxygen Lipids • fats and oils important for energy stores and some structures. Proteins • Vital for all sorts of functions! Nucleic Acid • Genetic material for all organisms Vitamins • Required for normal functioning.
All cells are made of 4 Biomacromolecules • These are really big molecules that make up 99% of most organisms. • These are: • LIPIDS • CARBOHYDRATES • PROTEINS • NUCLEIC ACID
Because of their size... Biomacromolecules are made up of subunits; meaning they are made of smaller parts that can be broken down or built up. The smaller parts are called subunits. Why do you think they need to be built up or broken down? Lipids are made of a glycerol and 3 fatty acids Carbohydrates are made of glucose chains Proteins are made of amino acid chains Nucleic acids are made of nucleotide chains
Lipids in cells • The most important functions of lipids • Storage of energy • The plasma membrane is made up of lipids.
Lipids • Most lipids are made of fatty acids tails and one glycerol. • Lipids can either be saturated or unsaturated. • Saturated Fats • Coconut oil • Butter • Beef • Pork • Cheese • Unsaturated fats • Olive oil • Peanut oil • Almonds • Sunflower oil • Corn oil • Fish • Mayonnaise • Margarines
Phospholipids • Special types of lipids, that have a phosphate head and 2 fatty acid tails. • The phosphate head is hydrophillic (water loving) and the fatty acid tails are hydrophobic (water hating)
The plasma membrane • The plasma membrane separates the cells internal environment from the external environment. • Controls the movement of substances into and out of the cell. • The membrane that surrounds cell organelles controls the movement of substances into and out of different organelles.
Phospholipid bilayer • The phospholipid bilayer is made up of many phospholipid molecules that have a hydrophilic (water loving) head and hydrophobic (water hating) tail. • They are arranged as a double layer with all the tails facing inwards and the heads around the outside.
Lipids and the plasma membrane Lipids are important components of membranes. Lipids are the fluid part of the membrane. Cholesterols give flexibility when cold and stability when hot.
Lipids and vitamins • Fats are needed in our diet for the absorption of many vitamins.
Proteins • Proteins are made up of subunits called amino acids. There are 20 different types of amino acids. Different combinations can made different types of proteins. AA AA AA AA AA AA
Structural proteins Keratin and Collogen
Metabolic proteins- ENZYMES • Catalasts- meaning they speed up chemical reactions! Enzymes break things down or build things up. http://www.youtube.com/watch?v=CZD5xsOKres
Carbohydrates • These are made up of sugar chain. They can be 1 sugar – monosaccharide, 2 sugar- disaccharide or longer – polysaccharide. • Carbohydrates are the biggest source of energy. • Cells break down carbs into glucose and use it to make ATP.
Carbohydrates in Cell Walls CELLULOSE
The mitochondria • The mitochondria is the site where carbohydrates or glucose is used to make ATP. It is the power supply of the cell. WHAT IS THIS PROCESS CALLED?
Other organelles important to biomacromolecules TRANSPORTATION
Endoplasmic reticulum • Folded membranes and tubules within the cytoplasm. • 2 kinds of endoplasmic reticulum rough ER and smooth ER. • Rough ER is caused by the ribosome being present on the surface Proteins produced by the ribosomes enter the ER and are then transported about the cell, they are finally exported out of the cell.
Golgi Body (Golgi apparatus) • Recieves protein products via the ER. Protein products are modified and stored in this structure before they are placed in vesicles for transport to the plasma membrane and released from the cell.
Nucleic Acids • DNA and RNA • They are information molecules. The hold the instructions for everything that is made by an organism’s body. • The DNA is located in the Nucleus of a eukaryotic cell. Why?
DNA Modelling! • Complete a DNA model.
A few things you should know! • Water is the main liquid in your body because: • It doesn’t boil at low temperatures or freeze at higher temperatures. • It keeps the temperature stable enough for chemical reactions. • It has a high surface tension meaning all the molecules stick together this allows cells to hold their shape by being filled up with water. Water is INCOMPRESSIBLE!
Other interesting chemicals • Pigments in animal and plant cells provide the colours in the world around us. Chlorophyll
Cells and Energy WHERE DOES THE ENERGY COME FROM?
ATP and Cells • All cells use a form of energy called ATP. • Adenosine Triphosphate is when this molecule is fully loaded with energy. • Adenosine Diphosphateis when it is not fully loaded with energy.
Making ATP • ATP is made from glucose in a process called CELLULAR RESPIRATION. Glucose ATP Cellular respiration
AUTOTROPHS • Autotrophs make their own glucose from sunlight. They undergo a process called photosynthesis (some bacteria undergo chemosynthesis instead).
HETEROTROPHS Heterotrophs get their energy from ...
Once the glucose has been made • BOTH Autotrophs and Heterotrophs must undergo cellular respiration to make ATP!
Making energy with and without oxygen. Aerobic respiration Occurs in the MITOCHONDRIA Anaerobic respiration LACTIC ACID STITCH
The products of anaerobic respiration in different organisms:
Pop Quiz • 20 Questions! Chapter 1 and 2