Cells Biology

HideShow resource information
  • Created by: rosie061
  • Created on: 16-09-13 04:25
Preview of Cells Biology

First 259 words of the document:

2.1: Cell Theory
2.1.1 Outline the Cell Theory:
Three main principles:
Living organisms are composed of cells
Cells are the smallest unit of life
Cells come from preexisting cells
2.1.2 discuss the evidence for the Cell Theory:
First Principle
Robert Hook:
First discovered cells 1665
Observing cork with a microscope he built himself
Drew cells and created the word cell
Antonie Van Leeuwenhoek:
Observed the first living cells
Discovered tiny `animalcules' (protozoa) in stagnant water
`Animalcules' Little animals
Single Lens microscope 200X
1983 found bacteria in Saliva
Mathis Schleding:
Stated in 1838 that plants are made of cells
Theodor Schwann:
Similar statement about animals 1839
Second Principle
Scientists have not been able to find any living entity that is not made of at least one
Rudolf Virchow:
Suggested that `all cells come from cells' 1855
Third Principle
Louis Pasteur:
1860s performed experiments
E.g. After sterilizing chicken broth by boiling, he showed that living organisms
would not `spontaneously' reappear. Only after exposure to preexisting cells was
life able to reestablish itself in the sterilized chicken broth
Robert Remak:
Discovered cell division under his microscope
2.1.3 State that unicellular organisms carry out all the functions of life
All organisms exist in either a unicellular or a multicellular form. They all carry out all the
functions of life:
Metabolism: includes all the chemical reactions that occur within an organism

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

Growth: limited but is always evident
Reproduction: involves hereditary molecules that can be passed to offspring
Response: to the environment is imperative to the survival of the organism
Homeostasis: maintaining a constant internal environment e.g. acidbase
Nutrition: providing a source of compounds with many chemical bonds which can
be broken to provide the organism with energy and nutrients necessary to
maintain life
2.1.…read more

Page 3

Preview of page 3

Here's a taster:

Volume: Affects functions of rate of heat and waste production and rate of
resource consumption. It affects the rate of chemical reactions to occur in the interior
of the cell
Surface Area: Controls what materials move in and out of the cells. Affects the
amount of materials able to move in and out of cells. Cells with more SA per unit
volume are able to move more materials in and out of the cells for each unit volume
of the cell.…read more

Page 4

Preview of page 4

Here's a taster:

Outline one therapeutic use of stem cells
Bone Marrow Transplants: Treat people with certain cancers
Stem cells found in bone marrow give rise to red blood cells, white blood cells
and platelets in the body
High doses of chemotherapy kills the cancer cells but also the normal cells in the
bone narrow. This means that the patient cannot produce blood cells.
1. Stem cells can be removed for themselves or a matching donor from the
pelvis using a needle
2.…read more

Page 5

Preview of page 5

Here's a taster:

Cell wall: Forms a protective outer layer that prevents damage from outside and
also bursting if internal pressure is high.
2.2.3 identify structures from 2.2.1 in electron micrographs of E.coli
2.2.4 State that prokaryotic cells divide by binary fission
Binary Fission: During this process, the DNA is copied, the two daughter
chromosomes become attached to different regions on the plasma membrane, and
the cell divides into two genetically identical daughter cells.…read more

Page 6

Preview of page 6

Here's a taster:

Mitochondrion: Carries out aerobic respiration
3. Golgi apparatus: Processes proteins before secretion
4. Plasma Membrane: Controls energy and exit of substances
5. Free ribisosmes: Synthesise protein for the use in cytoplasm
6. Lysosome: Stores digestive enzymes
7. Nucleus: Stores the genetic material
8. Central Vacuole: Storage and hydrolic functions
9. Lysosomes: Contain and transport enzymes.
10. Nucleolus: Involved in ribosome synthesize
11. Centrioles: Associated with nuclear division
12. Smooth Endoplasmic Reticulum: ER without ribosomes
2.3.3 Identify the structures in electron micrographs of liver cells
2.3.…read more

Page 7

Preview of page 7

Here's a taster:

Both have some sort of outside boundary that always involves a plasma
Both carry out all the functions of life
DNA is present in both
2.3.…read more

Page 8

Preview of page 8

Here's a taster:

Explain how the hydrophobic and hydrophilic properties of phospholipids help
maintain the structure of cell membranes
Phospholipids are both water soluble and not water soluble as they are
composed of a 3carbon compound, Glycerol. The two fatty acids are not
water soluble however the alcohol with phosphate is highly polar and is
soluble. One area is hydrophilic (water loving) and the other hydrophobic
(water fearing). These properties allow phospholipids to align as a bilayer if
water is present.…read more

Page 9

Preview of page 9

Here's a taster:

Explain passive transport across membranes by simple diffusion and
facilitated diffusion
Simple diffusion is when substances move between the phospholipids
molecules in the membranes
Facilitated diffusion is when substances are unable to pass between the
phospholipids and to allow these substances to diffuse through membranes
channel proteins are needed. Facilitated diffusion always causes particles to
move from a region of higher to lower concentration.…read more

Page 10

Preview of page 10

Here's a taster:

Vesicles bud off from the Golgi
apparatus and carry the modified
proteins to the plasma membrane
Endocytosis 1. Part of the plasma membrane is pulled
2. A droplet of fluid becomes enclosed
when a vesicle is pinched off
3. Vesicles can then move through the
cytoplasm carrying their contents
Exocytosis 1. Vesicles fuse with the plasma
2. The contents of the vesicle are
3. The membrane then flattens out again
2.4.…read more


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all resources »