10- 22-10

10-22-10

• In• Rewrite your hypothesis from the

“Eggs-periment”

10-22-10

• Through• Quiz• Cell notes

• OUT• NONE!!

Missed questions

• 1. Natural selection causes• A. Increase in the frequency of certain traits

within a population• B. Mutations in the DNA sequences of genes

within organisms• C. Changes in the non-living environment• D. The formation of fossils

Missed questions

• 2. New species form ______a. When organisms die and become

fossilizedb. When members of two different species

come together and mate to form a new species

c. As a result of natural selection over geologic time

d. Directly as a result of changes in their genes

• 3. The drug penicillin is used to kill bacteria. In the lab, you expose 1000 individual bacteria to penicillin and it kills 996 of the original bacteria. The four bacteria that survive were exposed to the penicillin again. Which of the following statements is true?

• A. The bacteria that survived could resist penicillin before the drug was delivered

• B. The bacteria that survived reproduced faster than the other bacteria

• C. The bacteria that survived changed themselves to be able to resist penicillin.

• D. The bacteria that survived learned how to resist penicillin

• 4. Group 1-spider, tiger, jellyfish, earthworm, dog, clam, hawk

Group 2—oak, tomato, redwood, cactus, wheat, apple, tree

Group 3—mushroom,mold,mildew, yeastThe three groups represent different _______a. Speciesb. Familiesc. Kingdomsd. classes

Cell Structure and Function

Cell organelles and what they do, from the outside in!

• Lipids -fat molecules• Lipid bilayer -cell membrane

fat molecules arranged in 2 layers prevents water soluble molecules from passing

• Protein molecules -receptor proteins, allows specific molecules to move in or

out of a cell

cytoskeletal

proteins

adhesion

protein

lipid bilayer

recognition

proteinrecepto

r protein

cytoplasmactive

transporter (calcium pump)

active transporter

(ATPase pump)

passive transporte

r

Cell Membrane

• The cell membrane consists of a phospholipid bi-layer in which proteins are embedded to varying degrees.

• Hydrophilic phosphate heads point toward the outside of the cell, while the hydrophobic lipid tails point inward toward the nucleus of the cell.

Cell membrane

The structure enveloping a cell, enclosing the cytoplasm and forming a selective permeability barrier. It is inside the cell wall in plant cells, while it is the only barrier between the outside of the cell and the cytoplasm in animal cells

Cell membrane

Phospholipid bilayer with embedded protein

Plants have cell walls attached to their cell

membranes

Cytoplasm

• Cytoplasm is a gelatinous, semi-transparent fluid that "fills" most cells.

• It contains all cell organelles except the nucleus and the cell membrane.

• All the functions for cell expansion, growth and replication are carried out in the cytoplasm of the cell

Mitochondria

• Mitochondria are sometimes described as "cellular power plants," because they generate most of the cell's supply of ATP, used as a source of chemical energy.

Mitochondria

Golgi apparatus• The primary function of the Golgi apparatus is

to process and package proteins synthesized by the cell (In the Endoplasmic Reticulum.)

• Some of these will eventually end up as integral membrane proteins embedded in the cell membrane.

• Other proteins moving through the Golgi will end up in lysosomes.

• Some proteins will be excreted by exocytosis.

Golgi Apparatus

Endoplasmic Reticulum

• The endoplasmic reticulum (ER) is responsible for the production of the protein and lipid components of most of the cell's organelles.

• The ER contains a great amount of folds - but the membrane forms a single sheet enclosing a single closed sac.

Endoplasmic Reticulum

Nucleus

• The nucleus contains most of the cell’s genetic material in the form of DNA.

• DNA is stored in structures called genes.

• Genes make up structures called chromosomes.

Animal cell with nucleus

Close up of nucleus

• Nucleolus and nuclear pores are shown.

Cell Processes

Passive transport

Passive transport is a means of moving substances across the cell membrane. Unlike active transport, this process does not require energy. Two main kinds of passive transport are diffusion and osmosis.