molecules make cells possible: sugars for energy proteins for building structures lipids for cell...
TRANSCRIPT
Molecules make Cells possible:
• Sugars for energy• Proteins for building structures• Lipids for cell membranes• DNA/RNA for making more cells• ATP for making energy possible
Prokaryotes vs. Eukaryotes
•DNA in single loop
•Very small•No organelles
•Live in all environments
•DNA in chromosomes in nucleus•Much larger•Organelles handle complex cell tasks•Live in restricted environments
Prokaryotic cells are structurally simpler than eukaryotic cells
Prokaryotic cell
Nucleoidregion
Nucleus
Eukar yotic cell Organelles
Colo
rized
TEM
15,
000
Figure 4.3A
Surface Area to Volume Ratio
A small cell has a greater ratio of sur face area to volume than a large cell of the same shape
30 m 10 m
30 m 10 m
Surface areaof one large cube 5,400 m2
Total surface areaof 27 small cubes 16,200 m2
Figure 4.2B
Eukaryotic cells—plants, fungi, animals, protists
• Nucleus present
• Membrane surrounds cell
• Cell wall may be present (plants, fungi, but NOT animals)
Plasma membrane• Surrounds entire cell• Made of two lipid layers• Allows certain molecules in/out =
“selectively permeable”
Nucleus—control center
Cytoskeleton—internal ‘skeleton’
Internal membrane system
3 important membranes:
1. Rough endoplasmic reticulum
2. Smooth endoplasmic reticulum
3. Golgi complex
• Smooth endoplasmic reticulum has a variety of functions:1. Synthesizes lipids 2. Processes toxins and
drugs in liver cells3. Stores and releases
calcium ions in muscle cells
Rough endoplasmic reticulum makes membrane and proteins Ribosomes on the sur face of the rough ER produce proteins that are secreted, inserted into membranes, or transported in vesicles to other organelles
• Lysosomes are sacs of enzymes that function in digestion within a cell
• Lysosomes in white blood cells destroy bacteria that have been ingested
• Lysosomes also recycle damaged organelles
The various organelles of the endomembrane system are interconnected structurally and functionally
Moving the cells around
3 ways:1. Flagellum—cell
extends cytoplasm into tail-like structure
2. Cilia—cell extends small hair-like structures
3. Pseudopodia—cell extends itself to move around
Human cells move too!1. Lung cells & fallopian tube cells
use cilia to move things around.
2. Male sperm cells use a flagellum to get to the egg.
3. White blood cells use pseudopodia to move between other cells and get to where they need to be.
Organelles
• Membrane surrounds them• Important organelles:
• Nucleus• Cell membrane• Lysosomes/peroxisomes• Rough endoplasmic reticulum• Smooth endoplasmic reticulum• Golgi apparatus• Special organelles involved in energy:
• Mitochondrion—produces ATP (in all eukaryotes)• In plants and some algae: Chloroplast—produces sugar
from light energy
Mitochondria
Chloroplast
Can human diseases result from organelles? Yes!
• Lysosomes• Mitochondria• Peroxisomes (in plants)• Even Cell Membranes!• Aging?• Chronic Fatigue Syndrome?
Quick Review!• What are 5 organelles in the cell?• In order, what organelles are responsible for
moving the products of DNA to the Golgi Complex?
• What 3 things make up the cell membrane?• What are the 4 foundational theories of
biology?• What are the 4 groups of biologically-
important molecules?