Biology Lab Exam 2

What is the role of oxygen in the ETC?

It takes up the electrons and protons and forms water.

What specifically, does the energy released by the "falling" electrons do to H+ ions (protons)?

Pumps protons against their concentration gradient

What 3 carbon (3C) molecule is produced at the end glycolysis?

Pyruvic acid

If you were observing a cell during mitosis and you saw that there were chromosomes lined up in the center of the cell, you would be looking at

metaphase.

Lytic Cycle

3) DNA immediately turns the cell into 2 viruses (producing factory) 4) the cells own machinery for DNA replication, transpiration, and translation, are hijacked and produce copies of the virus 5) the cell lyses and releases the phages

anaerobic threshold

where the body can no longer produce enough ATP energy with normal oxygen intake, can no longer perform aerobic respiration. the point at which anaerobic respiration occurs (respiration without the use of oxygen, either ethanol or lactic acid)

If you were designing a space station to produce its own food by shining LED lights onto plants, which LED color could be omitted from the space station?

yellow

chromosome structure

- 2 sister chromatids attached by a centromere; identical DNA

codons

- A codon is a tri-nucleotide sequence of DNA or RNA that corresponds to a specific amino acid. The genetic code describes the relationship between the sequence of DNA bases (A, C, G, and T) in a gene and the corresponding protein sequence that it encodes.

Citric acid cycle (Krebs cycle)

- Acetic acid (2-carbon) joins a 4-carbon acceptor molecule to form a 6-carbon product called citric acid - two CO2 produced (waste product) - harvest energy, some used to produce ATP, most is captured in the electron carriers NADH and FADH2 -cycle happens twice for each glucose molecule that fuels a cell. because glycolysis splits glucose in two - PRODUCES THE MOST HIGH ENERGY ELECTRONS

DNA structure

- DNA consists of nucleotides so it is a polynucleotide - Nucleotides: consist of three different molecules: 1. Phosphate: connected to a sugar (deoxyribose) b 2. Sugar: deoxyribose, connected to a nitrogenous base 3. Nitrogenous base: four different kinds

DNA polymerase

- Enzyme that make covalent bonds between the nucleotides of the new DNA strand

photon

- fixed quantity of light energy - the shorter the wavelength of light , the greater the energy of the photon

The Calvin Cycle

- HAPPENS IN THE STROMA - with each turn of the cycle there are difference chemical outputs and inputs 1) an enzyme adds each co2 to a 5-carbon sugar, the molecule breaks into two 3-carbon molecules 2) using energy from ATP and NADPH produced by light reactions, enzymes convert each 3-carbon molecule to a 3-carbon sugar 3) for every three molecule of CO2 that enter the cycle, the net output is one 3-carbon sugar 4) the other carbon sugar continue the cycle 5) using energy from ATP, earrange the remaining 3-carbon sugars to regenerate the 5-carbon sugars

types of cancer

- If the abnormal cells remain at the original site, the lump is called a benign tumor (does NOT spread) - Malignant tumors CAN spread into neighboring tissues and other parts of the body, forming new tumor, and can interrupt organ function

parental strands DNA

- In DNA replication, refers to the pre-existing single strand of DNA that is copied into a new strand of DNA via complementary base pairing.

introns

- Introns are removed by RNA splicing as RNA matures, meaning that they are not expressed in the final messenger RNA (mRNA) product - cut out during alternative splicing, they are not needed to code proteins, unnecessary information

two types of fermentation (anaerobic respiration)

- Lactic acid fermentation - Ethanol fermentation

Chloroplast structure

- Light-absorbing organelles- The site of photosynthesis - Found mostly in the interior cells of leaves - get their green color from chlorophyll, pigment (light-absorbing molecule) that plays a central role in converting solar energy to chemical energy

RNA processing

- Modification of RNA primary transcripts, including splicing out of introns, joining together of exons - one RNA can create many different kinds of mRNA depending on the exons in the mRNA and where they are spliced/connected

ETC

- NADH releases two high energy electrons to enter the chain - the chain is a series of electron molecules that past the electrons between them - with each exchange, a little bit of energy is released to can be used to make ATP - molecule at the bottom of the chain drops the electron to oxygen - oxygen picks up hydrogen, forming H2O - each chain acts a pump to uses the energy released by the falling electrons to move H+ ions across the membrane against their concentration gradient across the inner mitochondrial membrane - builds high potential energy in the H+ ions, allowing them to go through the ATP synthase - ACTIVE TRANSPORT - WHERE OUR CELLS MAKE THE MOST OF THEIR ATP

cancer reduction

- Not smoking - Exercise - Avoiding sun exposure - Eating high fiber-low fat diet - Performing self-exams - Regularly visiting a doctor to identify tumors

The light reactions

- chlorophyll in the thylakoid membrane absorb solar energy which is then converted to the chemical energy of ATP and NADPH - chlorophyll a is the specific pigment that absorbs light - when a pigment molecule absorbs a photon, one of the pigments electrons gains energy - photons excite electrons in the chlorophyll of the first photosystem - photons are then trapped by the primary electron acceptor. -

exons

- exons go on to be covalently bonded to one another in order to create mature mRNA. - exons are expressed, they are the pieces that get transcribed into mRNA

absorption of light (an electron)

- Pigments are usually molecule that have a lot of electrons that are relatively flexible - In pigment molecules, chlorophyl molecule. Some electrons can absorb light energy and can be elevated to a higher energy state (excited state), aka gaining energy - They are charged by absorbing light - when a pigment absorbs a photon one of the pigments electrons gain's energy - the electron is now "excited", which is highly unstable and gives off excess energy before falling back to the ground state-

Virus

- Protein capsule and genetic material - Nucleic acid wrapper in a protein coat

daughter strands DNA

- Refers to the newly synthesized strand of DNA that is copied via the addition of complementary nucleotides from one strand of pre-existing DNA during DNA replication.

centromere

- Region of a chromosome where the two sister chromatids attach - structure in a chromosome that holds together the two chromatids (the daughter strands of a replicated chromosome).

nature of light

- Sunlight is a type of energy called radiation, or electromagnetic energy - The distance between the crests of two adjacent waves is called a wavelength - The full range of radiation is called the electromagnetic spectrum -Increasing wavelength has less energy - Decreasing (shorter wavelength) has high energy - The visible light we see comes in different wavelengths, which correspond to different colors - Pigments in the thylakoid

cancer treatment

- Surgery: remove a tumor - Radiation therapy: parts of the body that have cancerous tumors are exposed to concentrated beams of high-energy radiation, which often harm cancer cells more than normal cells. Radiation therapy is often effective against malignant tumors that have not been spread - Chemotherapy: the use of drugs to disrupt cell division, is used to treat widespread or metastatic tumors

chromatids vs. chromosomes

- There are 46 chromosomes in our body, and hence 92 chromatids, just the double of chromosomes. - chromatids are the matching duplicate pairs of chromosomal information that are connected by a centromere to form a single chromosome

ethanol fermentation

- a form of anaerobic respiration found in yeast and bacteria - yeast performs cellular respiration and fermentation - produce ethyl alcohol as a waste product instead of lactic acid - also produces some CO2 in the process - this co2 is what causes bread to rise and causes the air bubbles in bread

does the ETC use passive or active transport? concentration gradient?

- active transport - pushes H+ ions from low to high concentration, AGAINST their concentration gradient - builds high potential energy

what organisms perform cellular respiration?

- all cells containing a mitochondria perform cellular respiration - animals ONLY do cellular respiration -plants need respiration to produce ATP

animal cytokinesis

- called "cleavage" - cleavage furrow: a ring of microfilaments in the cytoplasm - contracts around the cell - deepens the furrow and pinches the parent cell in two

Interphase

- cell makes new molecules and organelles. - two centrosomes form in the cytoplasm - chromosomes are duplicated within the nucleus, cannot be disguised individually, still in loosely packed chromatin fibers

lactic acid fermentation

- glycolysis produces ATP in the absence of O2 - w/out oxygen NADH must get rid of electrons without the ETC - lactic acid can store high energy electrons with out oxygen from NADH, but HAS LIMIT!! - much less ATP is produce, only two molecule per cycle

Photosynthesis + location

- happens in the CHLOROPLAST in the thylakoids - process whereas plants and certain bacteria transform light energy into chemical energy - use carbon dioxide and water as starting materials and releasing oxygen gas as a a by-product

Glycolysis

- happens in the cytoplasm - 6 carbon structure gets broken in half into two 3-carbon structures - Breaks down into two pyruvic acid - Produces two net ATP - Gain four high-energy electrons to NAD+, which forms NADH

Prophase

- in the nucleus, the chromatin fibers coil and they become thick and visible under a microscope - each chromosome exists as two identical sister chromatids that are joined by a centromere - in the cytoplasm, the mitotic spindle begins to form - nuclear envelope breaks into pieces - spindles attach to the centromeres and move the chromosomes towards the center of the cell

chloroplast

- leaves have the most chloroplasts - green color is from chlorophyll, a pigment (light absorbing molecule) - concentrated in the interior of the cell leaves - CO2 enters and O2 exits through tiny pores called stomata

Metaphase

- mitotic spindle is now fully formed - centromeres of all chromosomes line up between the two poles of the spindle - for each chromosome, the spindles attached to the two sister chromatids pull towards the opposite poles. - this tug of war keeps the chromosomes in the middle of the cell - the are on a linear plate

tRNA

- molecule interpreter - match amino acids to the appropriate codons to form the new polypeptide 1) pick up the appropriate amino acids 2) recognize the appropriate codons in the mRNA

are viruses alive?

- no they do not meet all seven criteria for being a living organism. - cannot reproduce without a host

pyruvate oxidation

- occurs in the space between membranes while entering the inner membrane of the mitochondria - pyruvic acid loses a carbon as CO2 (waste product) - the 2-carbon structure forms acetic acid - electrons are stripped from these molecules and transferred to another molecule of NAD+, forming more NADH - each acetic acid is attached to a molecule called coenzyme A (CoA) to form acetyl CoA

anticodon

- on one end of the folded RNA molecule is a special triplet of bases - anticodon triplet is complementary to a codon triplet on the mRNA - anticodon of the tRNA recognizes a particular codon on the mRNA - at the other end of the tRNA molecule is a site where one specific kind of amino acid attaches

Photosystems I and II

- part of the light reactions - cluster of a few hundred pigment molecules in each one, work as a light gathering antenna FIRST PHOTOSYSTEM -photons excite electrons in the chlorophyll - photons are trapped by the primary electron acceptor - replaces the lost electrons by extracting new ones from water - this step releases O2 during photosynthesis - energized electrons from the first photosystems pass down an ETC to the second photosystem - the chloroplast uses the energy released from this fall to make ATP (ATP IS NOT USED FOR. CELLULAR WORK) SECOND PHOTOSYSTEM - transfers its light-excited electrons to NADP+, converting it to NADPH

does the ATP synthase use passive or active transport? concentration gradient?

- passive transport - H+ ions fall from high concentration to low concentration

origin of DNA replication

- place where the replication bubble forms and begins

genes

- polynucleotide sequence with information for making one polypeptide - each codon codes for one amino acid - unit of inheritance in DNA consisting of specific nucleotide sequence that programs the amino acid sequence of a polypeptide

mRNA

- produced by transcription - once present, the information transcribed on the mRNA is used by the tRNA to create a specific amino acid - version of the gene that leaves the cell nucleus and moves to the cytoplasm where proteins are made.

histone

- protein structure that wrap the DNA around them

asexual reproduction (cell devision)

- reproduce by dividing in half, and the offspring are genetic replicas of the parents

sexual reproduction (cell division)

- requires fertilization of an egg by a sperm - involved a special type of cell division called Meiosis, which occurs only in reproductive organisms. - reproductive organisms do both mitosis (for growth) and meiosis (for reproduction)

Ribsomes (Translation)

- ribosomal RNA (rRNA) - allow a place for the tRNA to connect and read the mRNA - subunits of the ribosome act like a vise, holding the tRNA and mRNA molecules close together - the ribosomes can connect the amino acid from the tRNA in the site to the growing polypeptide

genetic code

- set of rules that convert a nucleotide sequence in RNA to an amino acid sequence

What contributes to variation in offspring in sexually reproducing organisms?

- sexual reproduction - independent orientation of homologous pairs during meiosis - crossing over of homologous chromosomes during tetrad formation

Anaphase

- sister chromatids of each chromosome separate - each is now considered a full fledged, daughter chromosome - chromosomes move toward opposite poles of the cell as the spindles shorten

chromosome duplication

- the DNA molecule of each chromosomes is copied through the process of DNA replication and new histone protein molecules attached as needed -each chromosomes consists of identical copies called sister chromatids, which contain the same genes - the two sister chromatids are joined together tightly at a narrow "waist" called the centromere - when the cell divides, the sister chromatids of a duplicated chromosome separate from each other - when a chromatid is separated form its sister, its is consider and full-fledge chromosome - one of the new chromosomes goes to one daughtr cell, and the other goes to the other daughter cell

ATP synthase

- the H+ concentrated on one side of the membrane rushes back "downhill" through the large protein - this action spins a component of the ATP synthase - this rotation activates parts of the synthase molecule that attach phosphate groups to ADP to create ATP - PASSIVE TRANSPORT

alternative splicing

- the idea that even if the same piece of DNA is used, alternative splicing can cute the DNA at different parts and combined different combinations of exons - this splicing variation can create many different mRNA and in turn code for many different protein products - one RNA can make many different kinds of mRNA depending on how it is spliced

chloroplast pigments

- they appear green because the light of that color is poorly absorbed by the chloroplasts - blue-violent and res-orange light are mainly responsible in photosynthesis

Telophase

- two groups of chromosome have reached opposite ends of the cell - telophase is the reverse of prophase - nuclear envelopes form, the chromosomes uncoil and the spindles disappear - cell splits in cytokinesis, the division of the cytoplasm into two cells

DNA replication

- two strands of parental DNA separate, each become a template for the assembly of a complementary strand from a supply of free nucleotides - nucleotides are lined up one a time along the template strand in accordance with the base pairing rules - enzymes link the nucleotides to form new DNA strands - the completed new molecules, identical to the parent molecules are called daughter DNA molecules

cancer cells

- uncontrolled cell division - can form tumors, abnormally growing masses of body cell

plant cytokinesis

- vesicles containing cell wall material collect at the middle of the cell - cell plate: vesicles fuse, form disk - membrane of the cell plate fuses with the plasma membrane - results in two daughter cells

what organism perform photosynthesis?

-plants do BOTH photosynthesis and respiration

transcription

1) Initiation of transcription - promoter: nucleotide sequence which is located in the DNA at the beginning of the gene which acts as a start signal - RNA polymerase attaches to the promoter 2) RNA elongation - the RNA grows longer, the RNA strand peels away from the DNA template, allowing the two DNA strand to come back together in the region already transcribed. 3) Termination of Transcription - terminator: sequence signals the end of the gene - the polymerase molecule detaches from the RNA molecule and the gene, and the DNA strands rejoin

translation

1) initiation - an mRNA molecules binds to a small ribosomal subunit - a special initiator tRNA binds to the start codon, where translation is to begin on the mRNA - the anticodon of tRNA carrying the amino acid, binds to the start codon 2) elongation - anticodon of an incoming tRNA molecule, carrying its amino acid, pairs with the mRNA codon in the A site of the ribosome - polypeptide leaves the tRNA in the P site and attaches to the amino acid on tRNA in the A site - the P site tRNA now leaves the ribosome, and the ribosome moves the remaining tRNA, carrying the growing polypeptide to the P site 3) termination - elongation continues until a stop codon reaches the ribosomes A site - completed polypeptide is freed and the ribosomes splits back into its subunits

virus infection process

1) phage binds to the cell and release its DNA into the cell 2) the injected DNA forms a barrier-like circle

The Cell Cycle

1. G 1 2. S Phase 3. G 2 3. Mitotic phase

four steps of cellular respiration + locations

1. Glycolysis (cytosol) 2. Pyruvate Oxidation (in the membrane as its entering the matrix) 3. Citric Acid Cycle (matrix) 4. ETC/ATP Synthase (inner membrane of the mitochondria)

Mitosis Phases

1. interphase 2. prophase 3. metaphase 4. anaphase 5. telophase (PMAT)

mutations

1.) Nucleotide substitution: mutation where a single nucleotide changes, changing that single overall codon 2.) Deletion: single nucleotide is missing, all following codons shift and change 3.) insertion: single nucleotide is added, codons shift and change - deletion and insertion affects ALL codons that follow it, substitution only affects ONE codon (unless it is a stop codon)

How many carbons exit out of the citric acid cycle during each round, as a waste product?

2

What TWO products of glycolysis enter into the mitochondria?

2 pyruvates

Lysogenic

3) the viral DNA is inserted in the bacterial chromosome = prophage 4) the host cell replicates the prophage DNA along with its cellular DNA - 2 daughter cells - can stay there indefinitely and create larger infections 5) occasionally a prophase leaves its chromosomes -can be triggered by an environment ex. mutagen

How many total carbons from the original glucose molecule enter the citric acid cycle? (Recall that TWO pyruvic acid, and thus two acetyl CoA, are formed from each glucose...)

4

What is the difference between mitosis and meiosis?

A single cell divides into two cells in mitosis but into four cells in meiosis.

At the end of all 3 steps of cellular respiration, where is most of the energy that was originally in the glucose molecule now being held in the cell (what molecule holds the energy)?

ATP

When an electron is passed from the primary electron acceptor in the first photosystem to the second photosystem, it travels through an electron transport chain. What is produced as the electron travels through this electron transport chain?

ATP

When hydrogen ions flow across the membrane through the molecular turbine (ATP synthase), what molecule is produced?

ATP

Which molecule would be found after the action of the enzymes in cellular respiration?

ATP

Some prokaryotic and all eukaryotic cells use oxygen to harvest energy from food molecules. In what form is that harvested energy available to power cell work?

ATP molecules

Is this movement of H+ ions an active or passive process?

Active.

DNA nitrogenous bases

Adenine (A), Thymine (T), Cytosine (C), Guanine (G)

RNA nitrogenous bases

Adenine (A), Uracil (U) , Guanine (G), Cytosine (C) - Thymine is replaced by Uracil

What will happen to the process of aerobic cellular respiration if no O2 is available in the cell?

Aerobic cellular respiration will stop.

When a photon of the correct energy is absorbed by a photosystem, an electron is energized and transferred to a primary electron acceptor. How is the missing electron replaced?

An electron from hydrogen made available by splitting water replaces the missing electron.

When is water formed during cellular respiration?

At the end of the ETC.

nucleotides

Basic units of DNA molecule, composed of a sugar, a phosphate, and one of 4 DNA nitrogenous bases

cellular respiration equation

C6H12O6 (glucose) + O2 -> CO2 + H2O

In which step of cellular respiration is most of the energy harvested from the glucose molecule?

Citric Acid Cycle

which stage of cellular respiration produces the most high-energy electrons?

Citric Acid Cycle

An organism's genetic information is stored within the sequence of _______. This information is transcribed into a sequence of _______, which are then translated into a sequence of _______.

DNA bases; RNA bases; amino acids

In which step of cellular respiration is most of the energy that was harvested from glucose transformed into an energy source that can be used to do cellular work?

ETC uses energy from high energy electrons to pump protons. ATP synthase actually makes the ATP.

which stage of cellular respiration produces the most ATP?

ETC/ATP synthase

The role of NAD+ in the citric acid cycle is the same as it was in glycolysis; namely, to "harvest" or "extract" the energy from glucose. What additional molecule helps with this process in the citric acid cycle? What, specifically, is being harvested by NAD+ and this other molecule?

FAD, electrons

photosynthesis Equation

H2O + CO2 + sun -> C6H12O6 (glucose) + O2

cellular respiration chemical cycling

IN: glucose (energy), O2 OUT: CO2, H2O (e- + O2), ATP (used for cellular work)

photosynthesis chemical cycling

IN: light (energy), CO2, H2O DURING: ATP (NOT used for cellular work, ONLY used internally for Calvin Cycle) OUT: glucose (energy), O2

Where does glycolysis occur?

In the cytosol

The s 3C molecule still has a lot of energy available. Where, specifically, is this energy located in this 3-carbon molecule?

In the electrons.

Where, specifically, is the Electron Transport Chain (ETC) located?

In the inner membrane of the mitochondria.

Where specifically does the citric acid cycle take place?

In the matrix.

What does a molecule of NADH or FADH2 do when it reaches the ETC?

It gives up its electrons.

A friend excitedly tells you of having inserted the sequence of the green fluorescent protein into an intron from a milk protein gene, planning to get rich by selling glow-in-the-dark milk. What should you say?

It won't work since introns are not expressed.

The ETC is made up of a series of protein complexes. Is the FIRST or the LAST of the protein complexes in the ETC more electronegative (remember that more electronegative means more attraction for electrons)?

Last.

What molecule does NAD+ become during glycolysis?Does NAD+ gain or lose electrons?

NADH, gain.

If a cell is unable to perform aerobic cellular respiration, what will then happen?

No ATP will be produced, causing all energy-requiring cell functions to cease.

When hydrogen ions flow across the membrane through the molecular turbine (ATP synthase), is this movement of H+ ions an active or passive process?

Passive

Does replication occur in one direction or both directions along the parental (old) strand?

Replication occurs in both directions.

double helix shape

The double helix is made up of two polynucleotide strands that wrap around each other. They are connect via the nitrogenous bases in the interior of the molecule.

Both cellular respiration and photosynthesis rely on electron transport chains embedded in membranes to produce ATP molecules. Which correctly describes the difference between the two types of electron transport chains?

The electron source in cellular respiration is glucose, while the electron source in photosynthesis is water

The figure shows an overview of the different entry pathways to cellular respiration for different macromolecules. Why are none of the digestive products entering the electron transport chain directly?

The electron transport chain only receives electrons carried by reduced electron carrier molecules such as NADH.

What happens, in terms of energy, as electrons move through the electron transport chain?

The lose energy.

What happens, physically, to the electrons in the electron transport chain?

The move from protein to protein in the ETC.

What is the name of the enzyme that add nucleotides to a growing DNA strand? What kind of bonds does this enzyme form between the nucleotides?

The name of the enzyme is the DNA polymerase. It creates covalent bonds between the nucleotides.

Sometimes a DNA mutation changes which nucleotide sits at a given position in a gene. How can this still result in a protein that is constructed correctly?

The nucleotide substitution creates a "new" codon that calls for the same amino acid as the "old" codon.

How many carbons from the original glucose molecule enter each round of the citric acid cycle?

The original glucose is six carbon. During glycolysis the molecule splits into two pyruvic acids, each made up of three carbons. Before the citric acid cycle, the pyruvic acid loses a carbon as CO2. It becomes acetic acid, which is a two carbon structure, which is how it enters a round of the citric acid cycle. So the answer is two carbon in each round.

What is the name of the locations that DNA replication begins along the DNA molecule?

The sites are called the origins of replication and replication bubbles. These are located as specific points in the double helix.

What do thymine (T) and cytosine (C) have in common, that makes them different from Adenine (A), and Guanine (G)?

Thymine and cytosine are both single ringed structures while adenine and guanine are larger, double-ringed structures.

You are given a sample taken from a living organism but are not told what kind of organism, only that it was denied oxygen in the container which held it. If you did a biochemical analysis, what would most likely be present in a sample of this organism?

alcohol or lactic acid

The image below is the summary equation for the process of photosynthesis. This reaction

builds food for the organism

What one carbon waste product of cellular respiration is formed as the 3 carbon product of glycolysis enters the mitochondria and becomes a 2 carbon Acetyl CoA?

carbondioxide

Where did the carbons in this waste product originally come from?

glucose

If you were using a light meter beneath a canopy of leaves, which color would you detect most?

green

RNA structure

in RNA, Thymine is replaced with Uracil, but other than that, they have the same chemical structure

One of the products of the citric acid cycle is CO2. This molecule is considered a waste molecule, since organisms performing aerobic cellular respiration will release it into the atmosphere. What reactant provided the carbon atoms used to produce this CO2?

pyruvic acid

If you found an RNA floating in the cytoplasm of a cell connected to one amino acid, you would have found what kind of RNA?

tRNA

It was through Watson, Crick, Wilkins, and Franklin's discovery of DNA structure that they and other scientists were able to develop a deeper understanding of

the function of DNA in living organisms.

Oxygen as O2 is required for aerobic cellular respiration. The function of O2 in this process is

to accept the spent electrons at the end of the electron transport chain