The Final Day

It's been quite a year and I'm surprised by feeling slightly sentimental about this final blog post, especially since I was quite literally ripping up my final test study notes just a few hours earlier.

What's done is done. I can't say I've enjoyed every minute of my year in biology, but I have enjoyed it, for the most part. I won't miss the Practice Standards or the tests though.

So yeah, that's it. Thanks for sticking around and reading through the woes of my junior year.

Have a nice life.

To Teacher, Professor, Sir, Authority Figure in Charge of My Grade

Hi,

I've updated my standards. I wasn't aware that we couldn't use our test results for Science Practice Standards so here's the link to the new updated SP 4 and SP 5

Thank you!

-Rena

Carbon Cycle Recap

The Carbon cycle is basically the combination between photosynthesis and cell respiration.

Cell respiration takes in oxygen and gives out carbon dioxide while photosynthesis takes in carbon dioxide and gives out oxygen.

So basically, it's a never ending cycle that maintains the balance of carbon dioxide and oxygen in the atmosphere.

Photosynthesis formula

An important thing that the carbon cycle contributes to is the removal of CO2 from the atmosphere, which is incredibly important since us humans burn tons of fossil fuels on a daily basis that just adds to the amount of CO2 in the atmosphere. 

So thank you plants for cleaning our air! 

Plant anatomy recap

Plant anatomy

Some notes

xylem carries water up

phloem carries water down

Flower anatomy

Some notes
Stamen is the male part
Carpel is the female part (also called pistil)

Photosynthesis Recap

Photosynthesis is basically the opposite of cell respiration. Instead of taking in oxygen and creating carbon dioxide, along with ATP, photosynthesis takes in carbon dioxide and releases oxygen.

Plant photosynthesis has two parts to it, light reaction and dark reaction. 

Light reaction takes place in the grana on the chloroplast. The first part of the light reaction is Photosystem II (PS2). In this part, water molecules get split into oxygen and hydrogen atoms. The electrons from the hydrogens are carried to the electron transport chain to provide energy to produce ATP by chemiosmosis. This step is called photophosphorylation because it uses light to provide energy.

The next step is Photosystem I (PS1). Light energy is absorbed once again. PS 1 is smilier to PS 2 except the end product is not ATP but NADPH.

So basically for light reactions,
PS2

1. Light is absorbed (680)
2. oxygen released; hydrogen ions move to ATP synthase
3. ATP produced

PS1

1. Light absorbed (700)
2. NADPH produced (carries H+ to Calvin cycle)

Dark Reactions are called dark reactions because there is no need for light absorption during this phase. It's also known as the Calvin Cycle.

This process is called carbon fixation. Basically, CO2 enters the Calvin cycle and becomes attached to a 5-C sugar to form a 6-C molecule. This molecule is unstable and immediately breaks down into 2 3-C molecules by the enzyme rubisco. The end product made is ADP and NADP, which go back into the cycle, and G3P, a 3-C sugar.


And that, in a large nutshell, is how we are able to live and breathe. Thank you plants!!

Cell Respiration Recap

Cell respiration takes place in the mitochondria of a cell. 

The first step to cell respiration, as we see in the picture above, is glycolysis. Glycolysis takes place in the cytoplasm of the cel and produces 2 ATP. In glycolysis, glucose is broken down into pyruvate and an electron is carried over to the electron transport chain by NADH. 

In between glycolysis and the Krebs Cycle, 2 Acetyl CoA are formed and 2 carbon dioxide molecules are formed as a byproduct. the Acetyl CoA then enters the mitochondria and undergoes the Krebs cycle, where NADH, carbon dioxide, FADH2 and ATP is formed.

The electron transport chain is where most of the ATP is formed. This step takes place in the mitochondrial membrane, or christae. The ETC carries electrons that were given by the NADH and FADH2 from glycolysis and the Krebs Cycle through redox reactions. ATP is formed through oxidative phosporolation and chemiosmosis and six water molecules are biproducts.

The chemical formula for cell respiration is written above in the image. Basically, oxygen molecules and glucose molecules undergo cell respiration to form carbon dioxide, water, and ATP. 

Day before the last: Labs throughout the Year

I've lost count of the days. This blog post is a little sentimental.

Here's a video of all the labs that I managed to record throughout the year. It's been one heck of a year.

Plant Transpiration Lab

Plant type	Normal (mL)	Fan (mL)	Heater (mL)	Lamp (mL)
Arrowhead	3.6	7.5	6.6	4
Coleus	0.9	6	3.9	3
Devil's Ivy	2.9	4.6	4.1	3
Dieffenbachia	4.1	7.7	6	3.9
English Ivy	1.8	5.1	3.2	2.1
Geranium	1.2	4.7	5.8	2.4
Rubber Plant	4.9	8.4	6.8	4.3
Weeping Fig	3.3	6.1	4.9	2.5
Zebra Plant	4.2	7.6	6.1	3.2

1. Describe the process of transpiration in vascular plants.

The process of transpiration is when vascular plants gain nutrients and release excess water/moisture.

2. Describe any experimental controls used in the Investigation.

Time. Each part of the experiment lasted one hour. 

3. What environmental factors that you tested increased the rate of transpiration? Was the rate of transpiration increased for all plants tested?

a) heat, light, wind, temperaure

b) yes, the rate of transpiration increased at some point for all plants tested,

4. Did any of the environmental factors (heat, light, or wind) increase the transpiration rate more than the others? Why?

Wind increased transpiration rates the most possibly because of osmosis. The water potential on the outside of the leaf is significantly less than the water potential on the inside of the leaf and therefore, more water is released from the leaf in an attempt to have a more balanced water spread.

5. Which species of plants that you tested had the highest transpiration rates? Why do you think different species of plants transpire at different rates?

The Rubber Plant had the highest transpiration rates possibly because the environment they naturally grow in calls for more transpiration to balance the water. 

6. Suppose you coated the leaves of a plant with petroleum jelly. How would the plant's rate of transpiration be affected?

Petroleum jelly would cover the stomata, effectively stopping all transpiration.

7. Of what value to a plant is the ability to lose water through transpiration?

Transpiration helps maintain the plant temperature as well has be an essential part to the photosynthesis process. Nutrients are also carried up from the roots to the stem by transpiration. 

Plant Hormones

Photo and information found at
http://www.plant-hormones.info/auxins.htm

Auxins - essential for plant body development

• stimulates cell elongation in stem
• stimulates cell division in cambium
• Stimulates differentiation of phloem and xylem
• Stimulates root initiation on stem cuttings and lateral root development in tissue culture 
• Mediates the tropistic response of bending in response to gravity and light 
• The auxin supply from the apical bud suppresses growth of lateral buds 
• Delays leaf senescence 
• Can inhibit or promote (via ethylene stimulation) leaf and fruit abscission 
• Can induce fruit setting and growth in some plants 
• Involved in assimilate movement toward auxin possibly by an effect on phloem transport 
• Delays fruit ripening 
• Promotes flowering in Bromeliads 
• Stimulates growth of flower parts 
• Promotes (via ethylene production) femaleness in dioecious flowers 

Photo and information found at
http://www.plant-hormones.info/abscisicacid.htm

Abscisic Acid - single compound; functions in plant development process

• Stimulates the closure of stomata (water stress brings about an increase in ABA synthesis). 
• Inhibits shoot growth but will not have as much affect on roots or may even promote growth of roots. 
• Induces seeds to synthesize storage proteins. 
• Inhibits the affect of gibberellins on stimulating de novo synthesis of a-amylase. 
• Has some effect on induction and maintenance of dormancy
• Induces gene transcription especially for proteinase inhibitors in response to wounding which may explain an apparent role in pathogen defense. 

Photo: http://biology.kenyon.edu/edwards/project/wendy/ethylene.htm
Info: http://www.plant-hormones.info/ethylene.htm

Ethylene - gaseous hormone; used in plant ripening

• Stimulates the release of dormancy. 
• Stimulates shoot and root growth and differentiation (triple response) 
• May have a role in adventitious root formation. 
• Stimulates leaf and fruit abscission. 
• Stimulates Bromiliad flower induction. 
• Induction of femaleness in dioecious flowers. 
• Stimulates flower opening. 
• Stimulates flower and leaf senescence. 
• Stimulates fruit ripening.

The Flowery Expedition

Flower #1

The petals were leaf-like. There were four petals. The inside had three flower-looking male parts.  The pollen was located within the flowers and the nectar was deep in the stem.

Flower #2
Dry petals. Rough. heavy, hard to access. 

Male and female parts located inside. Heavy organism like a bee would be able to open it. Ants and wind wouldn't do anything. 

Flower #3
Open, soft petals. Coloring acts like a runway to insects and animals. 

Pollen could not be seen. Nectar is probably down in the stem. Ants or tiny insects would be able to access it best. 

Flower #4
Bright red with yellow inner parts. Smooth petals. Male and female parts visible. Yellow pollen.

Not visible in picture, but ants were down inside the flower, searching for nectar.