Biology Journal 8/24/2015

How is this picture like the Endosymbiotic Theory? What would happen next, in this analogy?

Remember the 4 major pieces of evidence that support the Endosymbiotic Theory?

EndosymbiosisEndosymbiosisLike all evolution, eukaryotes evolved through a series of small steps.

Today!Get ready for your lab on osmosis. This lab will be counted as evidence. It will eventually all be put in your composition notebook.

• Read the entire lab• Decide where you want to put it, and write your

pre-lab questions, procedure, and materials.Do the homework questions for section 1.3Is there any other practice you’ve skipped? You can do the Endosymbiotic Theory worksheet, the Cells, Cells, They’re made of Organelles worksheet, the Measuring Magnification worksheet…

Today!Do your journal. Compare your answers with another classmate, and add to your journal anything they have that you didn’t think of.Get ready for your lab on osmosis. This lab will be counted as evidence. It will eventually all be put in your composition notebook.

• Read the entire lab• Decide where you want to put it, and write your

pre-lab questions, procedure, and materials.Do the homework questions for section 1.3Is there any other practice you’ve skipped? You can do the Endosymbiotic Theory worksheet, the Cells, Cells, They’re made of Organelles worksheet, the Measuring Magnification worksheet…

Biology Journal 9/14/12

What molecule is the macromolecule DNA made out of?

How did that molecule get its name?

Biology Journal 9/20/10

What do ribosomes do?

What other organelle are ribosomes often attached to?

What does that organelle do?

Biology Journal 11/21/13

How many cells do you think are in the average human’s body?

Biology Journal 11/22/13

What are histones?

What are chromosomes?

What’s the difference between the DNA of a eukaryote and the DNA of a prokaryote?

Biology Journal 11/27/13

The DNA of a prokaryote is called “naked.” Why is that? What’s different about the DNA of a eukaryote and a prokaryote?

1.2 Ultrastructure of cells: Eukaryotes have a much more complex cell structure than prokaryotes.

Nature of science: Developments in scientific research follow improvements in apparatus—the invention of electron microscopes led to greater understanding of cell structure.

Understandings:•Prokaryotes have a simple cell structure without compartmentalization.•Prokaryotes divide by binary fission.•Electron microscopes have a much higher resolution than light microscopes. •Developments in science, such as electron microscopy, can have economic benefits as they give commercial companies opportunities to make profits, but this can affect cooperation between scientists.

Applications and skills:•Structure and function of organelles within exocrine gland cells of the pancreas and within palisade mesophyll cells of the leaf.•Drawing of the ultrastructure of prokaryotic cells based on electron micrographs: cell wall, pili and flagella, and plasma membrane enclosing cytoplasm that contains 70S ribosomes and a nucleoid with naked DNA.•Drawing of the ultrastructure of eukaryotic cells based on electron micrographs: plasma membrane enclosing cytoplasm that contains 80S ribosomes and a nucleus, mitochondria and other membrane-bound organelles are present in the cytoplasm. Some eukaryotic cells have a cell wall.•Interpretation of electron micrographs to identify organelles and deduce the function of specialized cells.

International-mindedness: Microscopes were invented simultaneously in different parts of the world at a time when information travelled slowly. Modern-day communications have allowed for improvements in the ability to collaborate, enriching scientific endeavour. Theory of knowledge: The world that we inhabit is limited by the world that we see. Is there any distinction to be drawn between knowledge claims dependent upon observations made by sense perception and knowledge claims dependent upon observations assisted by technology?

Topic 1: Cell Biology (15 hours)

A cell is 32 µm across. A student draws it as 250mm wide. What is the magnification? Show your work.

Biology Journal 11/7/2014

A cell is 32 µm across. A student draws it as 250mm wide. What is the magnification?

You don’t have to draw it, but you can if that helps!

Actual size =Measured length

Magnification

32 µm =250 mm

x X= 7800

Solve for x

Convert to the same units before you divide!

7800 times magnified

250 mm1000 µm

1 mmx = 250000 µm

32 µm =250000 µm

x

Biology Journal 11/6/2014

What do you think could be the smallest things we can see with a light microscope?

What do you think could be the smallest things we can see with an electron microscope?

The kind of The kind of microscopes we microscopes we have used are have used are called light called light microscopes. microscopes.

A more A more powerful powerful microscope microscope is an is an electron electron microscope. microscope.

What do you think these could be?What do you think these could be?

1.2 The Ultrastructure of Cells

The invention of electron microscopes led to greater understanding of cell structure.

All organisms can be divided into two groups according to their cell structure.

Organisms

EukaryotesProkaryotes

Cell wall with peptidoglycan

Cell wall with cellulose (plants),

chitin (fungi), or no cell wall (animals)

70s ribosomes 80s ribosomes

Reproduces through binary

fission

Reproduces through mitosis

Germs! Smaller, simpler

You are a Eukaryote. Bigger, more complex

Eukaryotes are about 100 times Eukaryotes are about 100 times bigger than prokaryotesbigger than prokaryotes

Drawing of the ultrastructure of prokaryotic cells based on electron micrographs: cell wall, pili and flagella, and plasma membrane enclosing cytoplasm that contains 70S ribosomes and a nucleoid with naked DNA.

Example IB topic skill:

A Terrible Drawing…

Too lightUnlabeled

Messy

Tiny

Drawing of the ultrastructure of prokaryotic cells based on electron micrographs: cell wall, pili and flagella, and plasma membrane enclosing cytoplasm that contains 70S ribosomes and a nucleoid with naked DNA.

Parts are indistinguishable

Example IB topic skill:

A Good Drawing…

• Good use of space• Clear strong lines• Label lines are straight• Labels clearly written• Scale bar if appropriate

• Lines touch the labeled structure

• No unnecessary shading or coloring

NucleoidRegion where naked DNA can be found; may have plasmids (loops of “extra” DNA, which can introduce new genes)

FlagellaWhip like; allows the cell to move

PiliAllows cells to connect and exchange DNA (sexual reproduction)

70S Ribosomesmake protein

CytoplasmJelly-like substance Cell Wall

Made out of peptidoglycan (mesh of amino acids and sugars)

Cell MembraneMade out of phospholipids; controls what enters and leaves cell

Drawing of the ultrastructure of eukaryotic cells based on electron micrographs: plasma membrane enclosing cytoplasm that contains 80S ribosomes and a nucleus, mitochondria and other membrane-bound organelles are present in the cytoplasm. Some eukaryotic cells have a cell wall.

Example IB topic skill:

10µm

10µm

Plasma membrane

Mitochondria

Free 80S ribosomes

Lysosomes

Cytoplasm

Golgi apparatus Rough Endoplasmic Reticulum

Nucleus

NucleusDNA in a membrane

Cell Wall•In plant cells, it is made out of cellulose (a carbohydrate)•In fungi, it is made out of chitin (a carbohydrate)•Animal cells don’t have one

Golgi ComplexMakes vesicles for molecules to enter or leave the cell

80S RibosomesThey make protein; sometimes attached to ER Cytoplasm

Jelly-like substance

VacuoleLarge compartment for storage of water or other molecules

MitochondriaMakes energy by doing cellular respiration

Endoplasmic Reticulum

Transports molecules; can have ribosomes attached (rough) or none (smooth)

ChloroplastMakes glucose by doing photosynthesis

Cell wall

Nucleoid region(where DNA is located)

Cell membraneCytoplasm

(the darker spheres are ribosomes)

Pili

Flagella

Identify the structures in these false-colored microscopic images

Identify the structures in this false-colored microscopic image of a human liver cell

Cytoplasm Mitochondria Ribosomes(free)

Nucleus Endoplasmic Reticulum(rough)

LysosomeLysosome

Plasmamembrane

Identify the structures in this microscopic image of a plant cell (not false colored)

Cytoplasm(little dots are

ribosomes)

Chloroplast

Vacuole

Nucleus

Mitochondrion

CellWall

Plasmamembrane

This is a This is a sweatsweat gland gland attached to a hair attached to a hair follicle!follicle!

1. Which cell parts can we identify?

2. Which cells do you think…• Excrete water and lipids?• Make up the upper level

of skin (epidermis)?• Make up the fatty,

squishy layer of tissue under the skin?

This is a cross-section of a This is a cross-section of a leafleaf! How do some of ! How do some of the cells appear specialized for their job?the cells appear specialized for their job?

1. Which cell parts can we identify?2. Which cells do you think…

• Do photosynthesis?• Form a water-tight barrier?• Transport sugars and carbohydrates?

Biology Journal 11/25/2013

Eukaryotes Both Prokaryotes

Compare and contrast eukaryotes and prokaryotes in a Venn diagram.

Biology Journal 11/25/2013

Eukaryotes Both Prokaryotes

•Large and more complex•Have a cell membrane and cytoplasm

•Small and simple

•Has a nucleus and organelles

•Reproduce through asexual cell division

•Lacks a nucleus and lacks organelles

•DNA is linear and in many pieces (chromosomes)

Have ribosomes (but they are different)

•DNA is circular and in one piece (usually)

•Cells divide through mitosis

•Cells divide through binary fission

•Have 80s ribosomes •Have 70s ribosomes

•Attaches and transfers DNA through pili

Compare and contrast eukaryotes and prokaryotes in a Venn diagram.

Biology Journal 11/26/2013

Plant Both Animal

Compare and contrast plant and animal cells in a Venn diagram.

Biology Journal 11/26/2013

Plant Both Animal

•Have chloroplasts •Are eukaryotes•Often are high in lysosomes

•Has a plant cell wall

•Have other organelles in common (mitochondria, ER, golgi bodies…)

•Can have great ability to move

•Has a large vacuole

•Are similar in size

•No / very limited ability to move

•Cells asexually reproduce through mitosis

Compare and contrast plant and animal cells in a Venn diagram.

Extracellular Components – parts outside of the cell

The cell wall of plants•Gives the cell shape•Holds the cell up against gravity•Prevents it from exploding from too much water

Glycoproteins of animals•Made out of carbohydrates attached to proteins•Gives the cells adhesion•Anchors the cell to surrounding cells•Allow for movement

On your notecard, write…

1. Your name on the card2. One question that’s a definition3. One question that’s a drawing4. One question that’s an explanation5. Write the answers to these on the backside

Sarah Smith hr.1

What does flagella do?

What’s this thing?

Why do eukaryotes have to do mitosis, but prokaryotes don’t?

For exam

ple

For exam

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