Bio Exam 2

every energy transfer or transformation increases the entropy (disorder) of the universe

endergonic: the products have more free energy then the reactants
exergonic: the products have less free energy than the reactants

the hydrolysis of ATP to ADP and inorganic phosphate (Pi) releases energy

losing electrons

gaining electrons

simultaneously

are proteins produced in living cells that catalyze the metabolic processes of an organism. (increase the rate of chemical reactions.

extreme temperature and pH tends to denature enzymes

catabolic pathways release energy by breaking down complex molecules into simpler compounds. anabolic pathways consume energy to build complex molecules from simpler ones.

ATP + H2O --> ADP, Pi

to create ATP

they are needed to form NADH, FADH, and acetyl-CoA (which initiates the Krebs Cycle)

~ glucose is converted to 2 pyruvate molecules
~ 2 ATP and 2 NADH
~ occurs in the cytosol

~ Entry: acetyl-CoA + oxaloacetate --> citrate + CoA .... Rest of cycle: citrate + H2O --> 2 CO2 + 
    oxaloacetate + energy
~ forms 4 ATP and the rest of the energy is stored in NADH and FADH2
~ happens in the mitochondria of eukaryotes

~ (NADH or FADH2) + ½ O2 --> H2O + (NAD+ or FAD) + energy
~ 32 ATP
~ happens in the mitochondria

glycolysis leads to the production of acetyl-CoA which in turn initiates the start of the Krebs Cycle. The Krebs Cycle then provides the necessary NADH and FADH2 necessary for the ETC to operate.

aerobic requires oxygen and is also called cellular respiration.
anaerobic is similar but does not use oxygen.

C6H12O6 + 6 O2 --> 6 CO2 + 6 H2O + Energy (ATP + heat)

1. Glycolysis
2. Formation of acetyl-CoA
3. Krebs Cycle
4. Oxidative phosphorylation (ETC) .. not used for anaerobic respiration

green and yellow

chlorophyll

6 CO2 + 12 H2O --> C6H12O6 + 6 O2 + 6 H2O
(opposite of glycolosis)

plants, algae, and bacteria

chloroplast: where photosynthesis occurs
and the stroma: where the C3 Cycle occurs

• yellow-green and green are used most often. (chlorphyll a is the most abundant followed by chlorophyll b and charotenoids)

• deep red and blue/violet are least used.

• dependent reactions occur in the thylakoid and occur first.

• independent reactions include the C3 Cycle and C4 and CAM pathways for plants that have this process

the greenhouse effect is an accumulation of carbon dioxide. photosynthesis takes that carbon dioxide and turn is into oxygen, therefore counteracting it.

chloroplast

can only get energy directly from chemical compounds

get energy directly from light.

can fix carbon dioxide, thus they use it as a carbon cource

cannot fix carbon dioxide; the use organic molecules from other organisms as a carbon source.

carrots and sweet potatoes

• occurs in the thylakoid?

Steps:

• light is absorbed by photosystem II
  
• then energized electrons move down elctron transport chain. forming ATP
• light is then absorbed by photosystem I
• then light energy is converted to high energy molecules that are converted to NADPH
• water is split providing O2
  

consumes all of the products of the light reactions except oxygen.
12 H2O + 6 CO2 + light energy --> 6 O2 + C6H12O6 + 6 H2O

• carbon fixation (CO2 uptake)
• synthesis of G3P
• ribulose 1 5-bisphosphate (RuBP) regeneration
  

by using the eukaryotic cell cycle with mitosis or meiosis

two identical copies of a single chromosome that are connected by a centromere.
form the X shape.

- interphase:
      - G1 phase
      - S phase
      - G2 phase
- cell division:
      - mitosis
      - cytokinesis

Prophase
Metaphase
Anaphase
Telophase

plants develop a cell plate the starts in the middle and grows outward to meet the cell wall. Animal cells create a cleavage furrow and the cell split in two from that.

it functions in growth, cell replacement, and asexual reproduction

cancer is unregulated cell growth that involves the cells dividing excessively and can invade other issues to displace normal cells

this occurs several ways. one ways occurs during Prophase I of meiosis, the two chromosomes crossover causing variation. another way is provided by independent assortment where the combination of the arrangement of chromosomes can vary depending on how the chromosomes line up during metaphase I and II

pair of chromosomes that carry genes from the same inherited characteristics
      - one from "mom"
      - one from "dad"
ex: eye color

diploid cells have two complete sets of chromosomes whereas haploids have only one set of chromosomes

meiosis is used to form sex cells (gametes). this helps to not double organism's chromosome numbers every time reproduction occurs.

cell division that forms gametes.
2 divisions that form 4 haploid daughter cells
occurs in 2 stages: Meiosis I and Meiosis II

an exchange of chromosome segments that occurs between two chromosomes during prophase I in order to increase genetic variation.

where each pair of homologous chromosome orients itself on the metaphase plate independently of other pairs in Meiosis I. its is the possible combinations in one gamete.

the equally probable arrangements of chromosomes at metaphase I
think of the red and blue chromosomes from the picture.....

1. the cell goes through interphase, which includes the G1 phase, the S phase (DNA synthesis), and the G2 phase.
2. then the cell goes through the mitotic phase. which includes mitosis and cytokinesis,
   

growth of cancer cells beyond the original site

cancer that originates in the external or internal linings of the body.
Ex: skin

cancer in the tissues that support the body
Ex: bone, muscle

cancer in the blood forming tissues
Ex: bone marrow, spleen, lymph nodes

through radiation or chemotherapy

high energy radiation that is used to kill dividing cells.
It targets cancer cells, but can also destroy normal cells.

drugs that disrupt cell division.
Ex: Taxol - impairs the function of the mitotic spindle

chemicals (tobacco and alcohol)
certain infections ( caused by viruses and bacteria ex: HPV)
radiation (ex: UV radiation from sun or tanning beds)
lack of physical activity, poor diet, and obesity
environmental pollutants
heredity

Mitosis:
      •one DNA replication (interphase)
      •one division
      •results in two genetically identical daughter cells
      •homologous chromosomes
            –do not pair
            –do not cross-over
Meiosis:
      •one DNA replication (interphase)
      •two divisions (reductive division)
      •results in up to four genetically distinct daughter cells
      •homologous chromosomes
            –pair (synapsis)
            –cross over

different versions of genes
in other words... different variations of characteristics

a map of chromosomes

• Chromatin condenses to form chromosomes
• Each chromosome forms a pair of sister chromatids
• Mitotic spindle forms
      –Composed of microtubules and moves the chromosomes

• Chromosomes line up along the midplane of the cell the mitotic spindle

• sister chromatids separate and are moved toward opposite poles
      –each former sister chromatid can now be called a chromosome

• prophase is essentially reversed
      –Cell begins to divide
      –Mitotic spindle breaks down
      –Cytokinesis occurs

• divides the cell into two daughter cells
• cytokinesis usually begins in telophase and ends shortly after
• in animals, a cleavage furrow develops
    –results in two separate cells
• In plant cell, a cell plate develops
    –usually close to where the metaphase plate was
• also the chromosomes start to uncoil and form chromatin as the nucleolus begins to form 
  again

when cells only divide when they are attached to a surface

when cells continually divide until they touch one another