1. Cell Composition Mrs. Higgins, LVT Locust Trace Agriscience Center
Veterinary Assistant Program

2. Chemical Composition
Chemical composition plays an important role in cellular function.
Composition of protoplasm consists of:
Water: 85%
Protein: 10%
Lipids: 2%
Inorganic matter: 1.5%
Other (including carbs): 1.5%

3. Water Each cell is about 60-65% water
Intracellular fluid is about 40% water
Inside the cell
Extracellular fluid is about 20%
Outside the cell surrounding it
Might also hear the term interstitial fluid (cerebrospinal fluid, fluid in joints, in the eyes, and visceral spaces)

4. Water % is going to vary between species Also varies because of:
Age, condition, and state of hydration
How do we replace water in our body?
_____________
How do we eliminate water from our body?
_______________ and ______________
Drinking
Sweating
Urinating

5. Proteins Next largest component of cell Complex, high weight molecules
Proteins are made of amino acids
Classified in one of two ways
Structural: fibrous proteins like collagen, elastin, and keratin
Reactive: enzymes, protein hormones, and contractile proteins (muscle cells)

6. Proteins Proteins are also found on the cell membrane.
Serve a variety of functions:
Membrane receptor for hormones and drugs
Contributing to transport of water and particles in and out of cell
**Serving as markers to permit the immune system to recognize cells as normal or abnormal body components

7. Lipids Fatty substance Insoluble in water
Consist of carbon, hydrogen, and oxygen

8. Carbohydrates Carbon, hydrogen, and oxygen (CHO)
Simple sugars (monosaccharide)
Glucose: most prevalent simple sugar in body
Disaccharide (two simple sugars combined)
Sucrose (table sugar, glucose + fructose)
Lactose (milk sugar, glucose + galactose)

9. Carbohydrates Glucose: source of all cell energy
Glycolysis: enzymatic pathway that metabolizes glucose to produce energy
Multiple glucose molecules can be linked together to form a polysaccharide called glycogen
Two sites of glycogen synthesis
Liver: stored glycogen can be broken down into glucose to be used by the liver or secreted into the bloodstream
Skeletal muscle: glycogen stores can be used as an immediate source of energy for muscles (not able to be released into bloodstream)

10. Inorganic Matter 1-1.5% of cell composition
There are 24 elements represented in the body (cell). 20 of them represent <1% of the make-up
Electrolyte: also called “ion”
Any molecular substance that in solution dissociates into its electrically charged components
NaCl ->> Na+ and Cl-

11. Parts of the Cell

12. Parts of the Cell Parts of the cell includes: Cell membrane Cytoplasm
Organelles
Golgi apparatus
Endoplasmic reticulum
Mitochondria
Lysosomes
Nucleus

13. Cell Membrane Outer layer of the cell
Cell membrane varies among different types of cells (proteins)
Functions
Transport substances across membrane
Site for binding with substances in extracellular fluid
Cell to cell junctions
Recognition of other cells

14. Cell Membrane How do things get across the membrane? Type of Movement
Description
Simple Diffusion
Passive movement; Distribution of a substance in a solvent (water) so it becomes evenly concentrated (greater concentration to lesser concentration)
Facilitated Diffusion
Same except it requires a carrier system (see picture)
Osmosis
Movement of water across membrane. Must move through channels formed by proteins
Active Transport
Molecules can move against concentrations because of charge *requires energy*
Endocytosis and Exocytosis
In previous notes

16. Cytoplasm Material filling inside of the cell
Contains intracellular organelles and nucleus

17. Organelles
The intracellular structures that are organized for a particular job (all of the “things” inside the cell)
Example: Golgi apparatus, endoplasmic reticulum, ect.

18. Golgi Apparatus Varies in size and location in different cell types
Looks like a “stacked” membranous sac
Functions:
Cite of synthesis and packaging for secretory products. The Golgi encloses the product in a vesicle for release by exocytosis

19. Endoplasmic Reticulum
Membranous network found through cytoplasm.
Rough endoplasmic reticulum: has ribosomes attached. Production of proteins
Smooth ER: no ribosomes, stores lipids and steroids (carbohydrates)

20. Mitochondria Oval shaped organelle
Double wall provides large surface area
Produce energy for the cell
Produces ATP (adenosine triphosphate)

21. Lysosomes Membrane-bound vesicle of digestive enzymes
Must be in a membrane or the enzymes would kill the cell itself
Can engulf cell organelles that are damaged and remove them.
Can you name a cell that doesn’t have lysosomes?? ___________________
Red Blood Cells

22. Nucleus
Contains the genetic material of the cell encoded in molecules of DNA
Functions:
Regulate protein synthesis
Ensure the passage of genetic material (chromosomes) to subsequent generations of cells

23. Cell Division
Mitosis
Division of somatic cells to produce to identical daughter cells (all cells in body except sperm and eggs)
Divided into periods
Interphase
Prophase
Metaphase
Anaphase
Telophase

25. Cell Division Meiosis Division of reproductive cells
Reduces the number of chromosomes to half prior to fertilization
Like chromosomes are paired from each parent cell

27. Assignment