Bio Exam 3

Front 1

Powerhouses for the cell. Produce the cell’s ATP.

______malfunctions can have serious consequences for an individual’s health.

More than 100 genetic _______disorders have been identified, and all lead to energy shortage, muscle weakness and chronic fatigue.

Back 1

Mitochondria

Front 2

Three metabolic stages of cellular respiration:

Back 2

Glycolysis
Krebs cycle (a.k.a Citric Acid Cycle)
Electron transport chain and oxidative phosphorylation

Front 3

Glycolysis harvests chemical energy by ?

Back 3

breaking down glucose to pyruvate

Front 4

______is a catabolic pathway during which a six-carbon glucose is split into two three-carbon sugars, which are then rearranged by a stepwise process that produces two pyruvic acid molecules.

Back 4

glycolosis

Front 5

glycolosis Occurs in the ______
-Partially oxidizes glucose (C6) in two pyruvic acid (C3) molecules

Back 5

cytoplasm

Front 6

glycolosis:A multi-step pathway that takes place in the ______
Splits glucose to ______
Occurs________ O2

Back 6

cytoplasm
with or without
pyruvate

Front 7

The reactions of glycolysis occur in two phases

Back 7

1. Glucose activation phase2. Energy harvest phase

Front 8

-uses cellular ATP to phosphorylate (adds a phosphate group to) the glycolysis intermediates

-costs two ATP molecules per glucose

Back 8

glucose activation

Front 9

-produces ATP

-yields 4 ATP molecules per glucose

-2 molecules of NADH per glucose

Back 9

energy harvest

Front 10

Glycolysis is distinct from cellular respiration because

Back 10

Glycolysis does not occur in the mitochondria.

Front 11

If there is no oxygen present then the pyruvic acid molecules from glycolysis go through _______- anaerobic (takes place without O2)-No ATP production-results in the partial degradation of sugars-regenerates NAD+

Back 11

fermentation

Front 12

Two types of fermentation The two most common products of pyruvate reduction are either

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1. Alcohol fermentation2. Lactic acid fermentation

Front 13

How can glycolysis continue producing energy when oxygen is not present?

Back 13

Fermentation regenerates the NAD+ needed for glycolysis by allowing pyruvate to accept electrons and H+ from NADH

Front 14

How is champagne different from wine?

Back 14

Both are the result of alcohol fermentation. Yeast is allowed to consume the sugars in grapes. Alcohol is produced in the process.

With wine, this process is completed BEFORE being bottled up. With champagne, the fermentation process occurs INSIDE the champagne bottle.

This produces CO2 bubbles, which pressurize inside the bottle. This is why the cork flies off when you open it.

Front 15

You help a friend move, and the next day, your arms and legs are sore. What caused the soreness?

Back 15

Your overworked muscles did not get enough O2 and switched to fermentation, which builds up lactate.

Front 16

If there is NO oxygen around then _______ occurs following glycolysis. If there IS oxygen around, the pyruvic acid molecules from glycolysis go to the _________, followed by the ______ in cellular respiration- (ATP production
-results in the complete breakdown of sugars)

Back 16

fermentation
bridge reaction
Kreb’s cycle

Front 17

The reaction that connects glycolysis to the Krebs cycle is the _________
which converts pyruvic acid to acetyl CoA.

Back 17

bridge reaction

Front 18

Occurs in the mitochondrial matrix, the innermost part of the mitochondria.

-Completes the breakdown of glucose that glycolysis started.

Back 18

kreb's cycle

Front 19

The products of glycolysis and the Kreb’s cycle:

Back 19

-NADH and FADH2-a small amount of ATP generated

Front 20

Remember that for every molecule of glucose entering glycolysis there are _ pyruvate molecules that can enter the Krebs Cycle

Back 20

2

Front 21

two turns of the Krebs Cycle are needed to complete the
breakdown of__ glucose molecule.

Back 21

1

Front 22

So where’s all the energy??

Back 22

Stored in NADH and FADH2.

Front 23

-Located in the inner mitochondrial membrane
-Accepts energy in the form of electrons from NADH and FADH2
-Use the energy from electron transfers to make ATP via oxidative phosphorylation
-Produces most (90%) of the ATP of cellular respiration.

Back 23

---The electron transport system

Front 24

Electrons from NADH and FADH2 pass through a series of enzymes and other proteins called the ___________.

Their energy is used to pump H+ from the matrix into the intermembrane compartment. Creates a gradient.

Back 24

electron transport chain

Front 25

People who suffer from chronic fatigue are often recommended to take over-the-counter _____ pills.

These pills provide electrons that are needed to enter the electron transport chain and produce ATP for the cell.

Back 25

NADH

Front 26

KCN (potassium cyanide) capsules are dropped into a tank containing concentrated Sulfuric acid (H2SO4). This reaction produces deadly cyanide gas.

Cyanide binds to one of the proteins in the electron transport chain, preventing the passage of electrons and the production of ATP.

Cells stop producing ATP, killing them within minutes.

Back 26

the gas chamber

Front 27

The energy-coupling mechanism.

Back 27

Chemiosmosis

Front 28

The electron transport chain ______ make ATP directly.

it generates a proton gradient across the inner mitochondrial membrane.

Back 28

does not

Front 29

is the coupling of exergonic electron flow down an electron transport chain to endergonic ATP production by the creation of a proton gradient across a membrane.

Back 29

chemiosmosis

Front 30

is the site of chemiosmotic ATP synthesis.

Back 30

The inner mitochondrial membrane

Front 31

For every NADH that feeds into the electron transport chain__ protons are moved from the mitochondrial matrix to the intermembrane compartment.

Back 31

3

Front 32

For every FADH2 that feeds into the electron transport chain _ protons are moved from the mitochondrial matrix to the intermembrane compartment.

Back 32

2

Front 33

For every proton that crosses back into the mitochondrial matrix one ATP is synthesized by

Back 33

ATP synthase.

Front 34

Cells can switch off the pathways they don’t need by

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feedback inhibition

Front 35

The ratio of ATP/ADP reflects the energy state of a cell.

Energy high => ATP/ADP ___
Energy low => ATP/ADP ____

Back 35

high
low

Front 36

---______is the process in which the genetic information of a cell is passed along to the next generation of cells.

Involves the division of a parent cell into 2 daughter cells.

Back 36

cell division

Front 37

Characteristics of cell division

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Replication of DNA

Equal distribution of DNA to opposite ends of the dividing cell

Separation into two daughter cells

Front 38

During the cell cycle ____ alternates with mitosis (a.k.a. M phase)

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interphase

Front 39

the period of the cell cycle when the cell is not dividing)
makes up about 90% of the cell cycle

-high metabolic activity

-chromosomes and organelles are duplicated

Back 39

interphase

Front 40

Cell division consists of

Back 40

nuclear division and cytoplasmic division.

Front 41

______ is the division of the nucleus.

-During this process the DNA is equally distributed into 2 daughter nuclei.

Back 41

Mitosis

Front 42

Mitosis is the division of the nucleus.

-During this process the DNA is equally distributed into 2 daughter nuclei.

Back 42

cytokinesis

Front 43

During the cell cycle the ______ replicate.---______ are threadlike structures composed of chromatin, which is DNAand proteins bound to it.

Back 43

chromosomes

Front 44

The genome of a eukaryotic cell is organized into multiple chromosomes

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Genome
Chromosomes
Chromatin
DNA + proteins

Front 45

The eukaryotic chromosome has two “arms” which extend from a structure called the

Back 45

centromere

Front 46

After the DNA has replicated, there are now 2 chromosomes that are attached at the centromere.

These 2 chromosomes are called _________.

So, DNA replication produces a replicated chromosome with 2 identical _________.

Back 46

sister chromatids

Front 47

During ____ (cell division), the 2 sister chromatids separate, and each chromatid forms an individual chromosome.

These 2 chromosomes get split between the 2 daughter cells resulting from a ______.

Back 47

mitosis

Front 48

If the chromosomes are photographed, the pairs can be arranged by size, shape and staining pattern to produce a

Back 48

karyotype

Front 49

are a pair of chromosomes that contain the same genes. They have the same size, centromere position and staining pattern. These are not the same as replicated chromosomes. For each pair of homologous chromosomes, you received one chromosome from your mother and one from your father.

Back 49

Homologous chromosomes

Front 50

is the condition where cells have pairs of homologous chromosomes

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diploid

Front 51

Each species has a characteristic number of chromosomes and the individual chromosomes are distinguished by __,__,___. Human cells contain __ chromosomes, __ pairs of homologous chromosomes. 

Back 51

size, shape, and staining pattern-
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Front 52

Humans: _____ (22 pairs) + 1 pair of sex chromosomes------_____ are the non-sex chromosomes

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autosomes

Front 53

Some cells have only half of the set of chromosomes and are called ____.---_____ is the condition in which cells contain one set of chromosomes.No pairs. -the ____ condition is found only in the gametes.

Back 53

haploid

Front 54

are haploid egg or sperm cells and contain half the number of chromosomes of ordinary cells.

Back 54

gametes

Front 55

Two haploid gametes unite during fertilization to form a _____ (a fertilized egg).

---____ is a diploid cell that results from the union of two haploid gametes.

Back 55

zygote

Front 56

The mitotic phase (M-phase) of the cell cycle is divided into five phases

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EARLY PROPHASE, LATE PROPHASE, METAPHASE, ANAPHASE AND TELOPHASE

Front 57

This is part of the cytoskeleton in eukaryotic cells.

It separates the chromosomes into the daughter cells during cell division.

Remember, during S-phase, prior to cell division, the chromosomes duplicate. So each duplicated chromosome consists of a pair of sister chromatids.

Back 57

spindle apparatus

Front 58

-chromatin condenses-spindle apparatus forms

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Mitosis – Early Prophase

Front 59

These are protein structures on chromosomes where spindle fibers attach during mitosis.

Think of these as handles on the chromosomes that the spindle fibers hold onto.

Back 59

Kinetochores

Front 60

-nuclear envelope disappears

-Microtubules from spindle attach to the kinetochore of chromosomes

-polar microtubules radiate toward the cell’s equator. Each microtubule attaches to a separate sister chromatid.

Back 60

late prophase

Front 61

-chromosomes move to and align on the equator of the cell.

Back 61

metaphase

Front 62

-sister chromatids divide into separate daughter chromosomes and move toward opposite poles.

-movement of the chromosome is accomplished by depolymerization of the microtubules at the kinetochore. (they break apart).
-cell begins to elongate because the polar microtubules slide past
each other and push the poles apart.

Back 62

anaphase

Front 63

-daughter chromosomes arrive at poles

-kinetochore microtubules disappear

-polar microtubules elongate (pushing out on the ends of the cells)
helps causes the formation of the cleavage furrow.daughter nuclear envelopes form

-chromatin begins de-condensing.

Back 63

telophase

Front 64

By the end of telophase replication of the nucleus is complete and two______are present.

Back 64

genetically identical daughter nuclei

Front 65

Only one parent
Single parent passes on all its genes
Rare genetic differences in offspring are the result of DNA changes, or mutations

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asexual reproduction

Front 66

Two parents give rise to offspring
Each parent passes on half its genes
Greater genetic variation with offspring being genetically different from their parents and siblings

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sexual reproduction

Front 67

is a pre-requisite for sexual reproduction.

Occurs in the ovaries and the testes in mammals.

A meiotic division followed by 2 rounds of cytokinesis to produce 4 daughter cells that become gametes (sperm or egg).

Gametes carry HALF the genetic material of the parent. So the cells produced by ______are not identical to the parent cell.

Back 67

meiosis

Front 68

Meiosis reduces chromosome number from diploid to _____.


-_____ replication precedes meiosis (just like mitosis).

In meiosis, each daughter cell receives one member of each pair of homologous chromosomes

Back 68

haploid
chromosomes

Front 69

A second division, called ____separates the sister chromatids and puts one chromatid into each daughter nuclei.

So, at the end of meiosis, there are __ haploid daughter nuclei, each with one copy of each homologous chromosome.

Back 69

meiosis II
4

Front 70

Homologous chromosomes undergo pairing up
Sister chromatids are linked at centromeres, non-sister chromatids are linked at chiasmata
Genetic crossing over occurs, exchange of genetic info between un-identical chromosomes.

Back 70

Unique events occur during meiosis I

Front 71

-Chromosomes condense
-Homologous chromosomes undergo pairing up

Back 71

MEIOSIS I
Prophase I

Front 72

-Sister chromatids are linked at centromeres, non-sister chromatids are linked at chiasmata
-Genetic crossing over occurs

Back 72

MEIOSIS I
Prophase I

Front 73

are the regions of paired homologous chromosomes where
chromatids have exchanged genetic material because of crossing over

Back 73

chiasmata

Front 74

nuclear envelope disappears

Back 74

MEIOSIS I
Prophase I

Front 75

-chromosome pairs align at the equator, called the metaphase plate
-kinetochores of sister chromatids face same pole
-centromeres of homologues face opposite poles.

Back 75

MEIOSIS I
Metaphase I

Front 76

-spindle microtubules interact with kinetochore fibers
-homologous chromosomes move toward opposite poles
-sister chromatids remain attached (this is different than mitosis)

Back 76

MEIOSIS I
Anaphase I

Front 77

-chromosomes arrive at poles
-cell divides

Back 77

MEIOSIS I
Telophase I and
cytokinesis

Front 78

nuclear membrane that was reformed at telophase I breaks down

Back 78

MEIOSIS II
Prophase II

Front 79

-Chromosomes align at metaphase plate as in mitosis

Back 79

MEIOSIS II
Metaphase II

Front 80

-Sister chromatids separate and move toward opposite poles

Back 80

MEIOSIS II
Anaphase II

Front 81

-nuclei form at opposite poles

Back 81

MEIOSIS II
Telophase II and cytokinesis

Front 82

-cell division occurs
-four haploid daughter cells are the final result

Back 82

MEIOSIS II
Telophase II and cytokinesis

Front 83

_____ is a unit of DNA that encodes information needed to produce proteins, cells, and entire organisms
Can be a few hundred to many thousands of nucleotides in length
The location of a gene on a chromosome is called its _____

Back 83

gene
locus (or loci)

Front 84

-Each species has a characteristic number of chromosomes  -Human cells contain __chromosomes,__ pairs.
Humans: _______ (22 pairs) + 1 pair of sex chromosomes---______ are the non-sex chromosomes.

Back 84

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autosomes

Front 85

____ are sequences of nucleotides at specific locations on chromosomes

__________ carry the same kinds of genes for the same characteristics

Genes for the same characteristic are found at the same_____ on both homologous chromosomes

Back 85

genes
Homologous chromosomes
loci

Front 86

Genes for a characteristic found on homologous chromosomes may not be identical

Alternative versions of genes found at the same gene locus are called _____.

_____ are formed by mutations.

Back 86

alleles

Front 87

An organism’s two alleles may be the same or different
Each cell carries two alleles per characteristic, one on each of the two homologous chromosomes
If both homologous chromosomes carry the same allele (gene form) at a given gene locus, the organism is _____at that locus-- If two homologous chromosomes carry different alleles at a given locus, the organism is ______ at that locus, also called _____.

Back 87

homozygous
heterozygous
hybrid

Front 88

_____________predicts offspring genotypes and phenotypes from combinations of parental gametes

Assign letters to the different alleles of the characteristic under consideration (uppercase for dominant, lowercase for recessive)

2. Determine the possible gametes from both parentsWrite the gametes from each parent, along each side of a 2 x 2 grid (Punnett square)

4. Fill in the genotypes of each pair of combined gametes in the grid.
5. Determine the genotypic ratio based on the outcome of the Punnett Square.

6. Based on the which traits are dominant, and which are recessive, calculate the predicted phenotypic ratio.

Back 88

The Punnett square method

Front 89

How Were the Principles of Inheritance Discovered?

Back 89

Gregor Mendel - Austrian monk in a monastery in the late 1800s
--Discovered patterns of inheritance and many essential facts about genes, alleles, and the distribution of alleles in gametes during sexual reproduction
He chose edible pea plant for his experiments
Allowed him to see patterns in the way plant characteristics were inherited

Front 90

Why Pea plants?

Back 90

Pea flowers have stamens, the male structures that produce pollen. Pollen contains the sperm (male gametes); sperm are gametes and pollen is the vehicle

Pea flowers have carpels, female structures housing the ovaries, which produce the eggs (female gametes)

Pea flower petals enclose both male and female flower parts and prevent entry of pollen from another pea plant

Front 91

Because of their structure, pea flowers naturally _______

Pollen from the stamen of a plant transfers to the carpel of the same plant, where the sperm then fertilizes the plant’s eggs

Back 91

self-fertilize

Front 92

Mendel was able to mate two different plants by _________
Female parts (carpels) were dusted with pollen from other selected plants

Back 92

(cross-fertilization)

Front 93

The key to Mendel’s success:

Back 93

He chose a simple experimental design

He chose to study individual characteristics (called traits) that had unmistakably different forms, such as white versus purple flowers

He started out by studying only one trait at a timeHe followed the inheritance of these traits for several generations, counting the numbers of offspring with each type of trait

By analyzing these numbers, he saw the basic patterns of inheritance emerge

Front 94

How Are Single Traits Inherited?

Back 94

Pea plants that are homozygous for a particular characteristic always produce the same phenotype

Front 95

A ______is the mating of pollen and eggs (from same or different parents)

Back 95

genetic cross

Front 96

Mendel’s flower color experiments:

Back 96

Crossed a true-breeding (homozygous) purple flower plant with a true-breeding (homozygous) white-flower plant (the P generation)

The F1 generation consisted of all purple-flowered plants

Front 97

The inheritance of dominant and recessive alleles on homologous chromosomes can explain the results of Mendel’s crosses

Back 97

Each trait is determined by pairs of genes; each organism has two alleles for each gene, one on each homologous chromosome.
When two different alleles are present in an organism, the dominant allele may mask the recessive allele, even though the recessive allele is still present
The pairs of alleles on homologous chromosomes separate, or segregate, from each other during meiosisChance determines which allele is included in a given gameteTrue-breeding organisms have two copies of the same allele for a given gene and are homozygous for that gene; hybrid organisms have two different alleles for a given gene and are heterozygous for that gene

Front 98

The particular combination of the two alleles carried by an individual is called the ______

The physical expression of the genotype is known as the _____ (for example, purple or white flowers)

Back 98

genotype
phenotype

Front 99

______ is used to deduce whether an organism with a dominant phenotype is homozygous or heterozygous
Cross the unknown dominant-phenotype organism (P_) with a homozygous recessive organism (pp)
If the dominant-phenotype organism is homozygous dominant (PP), only dominant-phenotype offspring will be produced (Pp)
If the dominant-phenotype organism is heterozygous (Pp), approximately half the offspring will be of recessive phenotype (pp)

Back 99

test cross

Front 100

How is sex determined in the offspring?

Back 100

Mammals have a set of sex chromosomes that dictate gender
Females have two X chromosomes


Males have an X chromosome and a Y chromosome


The rest of the (non-sex) chromosomes occur in identical pairs and are called autosomes

Front 101

In the genes studied by Mendel, one allele was dominant over the other, which was recessive
Some alleles, however, are incompletely dominant over others
When the heterozygous phenotype is intermediate between the two homozygous phenotypes, the pattern of inheritance is called

Back 101

incomplete dominance

Front 102

Human hair texture is influenced by a gene with two incompletely dominant alleles, _______ an ___
A person with two copies of the__ allele has curly hair
Someone with two copies of the__ allele has straight hair
Heterozygotes (with the ____ genotype) have wavy hair

Back 102

C1 and C2
C1
c2
C1C2

Front 103

An individual may have at most two different gene alleles
A species may have ________for a given characteristic
However, each individual still carries two alleles for this characteristic

Back 103

multiple alleles

Front 104

Human blood group genes produce blood types A, B, AB, and O
There are____ in this system: A, B, and o

Back 104

three alleles

Front 105

__ and ___ code for enzymes that add different sugar molecules to the ends of glycoproteins that protrude from red blood cells

______ codes for a nonfunctional enzyme that doesn’t add any sugar molecules

Blood types A, B, AB, and O arise as a result of the actions of these alleles

Back 105

Alleles A and B
allele o

Front 106

People with AA or Ao genotypes have blood type _; people with BB or Bo genotypes have blood type _; people with oo genotypes have blood type _

Back 106

A
B
O

Front 107

AB individuals have both the A and the B allele, so they produce both types of enzymes
Consequently, the plasma membranes of their red blood cells have both A and B glycoproteins

When heterozygotes express the phenotypes of both of the homozygotes (in this case, both A and B glycoproteins), the pattern of inheritance is called

Back 107

codominance

Front 108

People make antibodies to the type of glycoproteins they __
People with type A blood make B antibodies; people with type B blood make A antibodies
People with type O blood make both type A and type B antibodies; type AB blood groups make no antibodies

Back 108

lack

Front 109

The antibodies cause red blood cells that bear foreign glycoproteins to

Back 109

clump together and rupture

Front 110

Type __ blood, lacking any sugars, is not attacked by antibodies in A, B, or AB blood, so it can be transfused safely to all
Universal donorBecause people with type__blood produce both A and B antibodies, they can receive blood only from other type __ donors
Their antibodies would attack any donated blood cells bearing A or B glycoproteins

Back 110

o

Front 111

The environment influences the expression of genes

Back 111

The environment in which an organism lives profoundly affects its phenotype

Front 112

Some human genetic disorders are sex-linked

Back 112

The X chromosome contains many genes that have no counterpart on the Y chromosome
Because males have only one X chromosome, they have no other allele to exert dominance over a sex-linked (X-linked) allele causing disease

Front 113

The incorrect separation of chromosomes in meiosis is known as
-______ causes gametes to have too many and too few chromosomes
Most embryos that arise from fusion of gametes with abnormal chromosome numbers spontaneously abort, but some survive to birth and beyond

Back 113

nondisjunction

Front 114

Some genetic disorders are caused by abnormal numbers of autosomes
_________, afflicted individuals have three copies of chromosome 21
______includes several distinctive physical characteristics, including weak muscle tone, a small mouth held partially open because it cannot accommodate the tongue, and distinctively shaped eyelids
______is also characterized by low resistance to infectious diseases, heart malformations, and varying degrees of mental retardation, often severe

Back 114

In trisomy 21 (Down syndrome)