Laura Eberhardt
Cells
Chapter 3
1. Cells and cell theory
à basic unit of structure and function
àvirus
Cytology – the study of cells
cell theory:
1) one or more cells
2) life functions (metabolic processes)
3) come from pre-existing cells
2. Structure of a generalized animal cell
à cell membrane
à cytoplasm
à most have a nucleus
à organelles
à cells vary greatly (size shape, complexity)
3. Cell membrane
a) structure
à protein & lipid
à fluid mosaic model (proteins floating in lipids)
i) proteins act as receptors that will bond with
chemicals or act as gates for passage in/out of cell.
ii)Lipids have a phosphate atom attached to lipid
(phospholipid)
Thursday, September 11, 2014 at 12:30:44 PM Eastern Daylight Time
34:15:9e:2f:3a:92
Laura Eberhardt
Cells
Chapter 3
b) membrane transport
semipermeable = some materials can enter/exit the cell while others can not
i)
simple diffusion
à must be small
H à L
(no energy needed)
Pass through lipid portion so must be soluble in lipids
(O2, CO2, steroids)
If not soluble in lipids must pass through the protein
gates. (water, Na+, K+, Ca+2
ii) facilitated diffusion
iii) active transport
4. Cytoplasm
Thursday, September 11, 2014 at 12:30:44 PM Eastern Daylight Time
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Laura Eberhardt
Cells
Chapter 3
5. Cell organelles
organelle = “little organ”
a) nucleus
* Some cells have no nucleus (
) and some have many (
-_______________ structure in the cell
-Contains genetic material (DNA)
Function: control center of the cell
b) endoplasmic reticulum
-A series of tubes that connects one area of the cell to another
-can be smooth or rough:
-smooth ER – no ribosomes on surface
-rough ER – has ribosomes on surface
Function: internal transport
c) ribosome
- smallest parts that contain RNA
- Found on some ER or free floating in cytoplasm
Function: site of protein synthesis
d) Golgi complex
-Consists
of a series of flattened disks (sacks)
Function: packages proteins and lipids for use either inside or
outside of cell.
Thursday, September 11, 2014 at 12:30:44 PM Eastern Daylight Time
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)
Laura Eberhardt
Cells
Chapter 3
e) mitochondria
-100 to several thousand per cell!
- oval structures having an inner and outer membrane
- generates ATP (Adenosine triphosphate) or ______________
Function: site of cellular respiration
f) vesicle = vacuole
- small spheres that contain a wide variety of materials
- ex:
Function: Storage
g) lysosome
-small
vesicles that contain powerful digestive enzymes
-nick-named “suicide bags”
Function: breakdown materials within the cell
h) centrosome / centriole
-Organelles involved in cell division
Function: pull chromosomes and organelles into the two separate
daughter cells
6. Cell membrane specializations
a) flagella
-long, whip-like structure used to propel sperm through fluid.
Thursday, September 11, 2014 at 12:30:44 PM Eastern Daylight Time
34:15:9e:2f:3a:92
Laura Eberhardt
Cells
Chapter 3
b) microvilli
- microscopic, finger-like projections
Function: greatly increases the surface area for absorption (lining
of intestines)
c) cilia
long hair-like structures
Function: movement of materials that are external to cell (throat)
7. Cellular physiology
a) cell division
Mitosis: results in each daughter cell having the same number of
chromosomes as the parent cell
Meiosis: results in each daughter cell having half the number of
chromosomes as the parent cell (gametes)
b) cellular respiration (mitochondria)
the breakdown of one molecule of glucose to gain 36 ATP
step 1. GLYCOLYSIS à occurs in the cytoplasm
step 2. KREBS CYCLE
step 3. ELECTRON TRANSPORT CHAIN
Thursday, September 11, 2014 at 12:30:44 PM Eastern Daylight Time
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Laura Eberhardt
Cells
Chapter 3
c) protein synthesis
-how cells manufacture new proteins (enzymes, proteins etc.)
step 1. TRANSCRIPTION – mRNA is made from the DNA template.
The RNA brings the message to a ribosome in the cytoplasm
step 2
TRANSLATION – tRNA brings Amino Acids to the
ribosome. Amino Acids bond together forming a polypeptide.
8. Disorders
a) cancer
Cell division without stopping. Produces a mass of cells (tumor)
benign tumor is not life-threatening
malignant tumor – is life-threatening
The spread of cancer from one tissue to another is called metastasis.
Types of Cancer
1.
2.
3.
4.
Carcinoma – cancer of the epithelial tissue
Melanoma – cancer of the skin
Sarcoma – cancer of the muscle
Lymphoma – cancer of lymphatic tissue
Thursday, September 11, 2014 at 12:30:44 PM Eastern Daylight Time
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