Ib Biology Year 1 Topic 1: Cell Biology

Front 1

According to the ____ ______, living organisms are composed of cells.

Back 1

Cell theory

Front 2

True or false: Organisms consisting of only one cell carry out most of the functions of life in that cell.

Back 2

False; Organisms consisting of only one cell carry out all functions of life in that cell.

Front 3

Multicellular organisms have properties that emerge from the interaction of
their cellular components. What are these properties called?

Back 3

Emergent properties

Front 4

Specialized tissues can develop by cell _______________ in multicellular
organisms.

Back 4

Differentiation

Front 5

The capacity of stem cells to divide and differentiate along different
pathways makes them suitable for what two uses in humans?

Back 5

1) embryonic development

2) treatment of diseases

Front 6

Name three examples of cells that get especially elongated and contain multiple nuclei.

Back 6

Striated (skeletal) muscle, giant algae, fungal hyphae

Front 7

List two diseases that can be treated using stem cells and what they affect.

Back 7

1) Stargardt's disease: mutation in the cells of the eye cause the retina to be damaged

2) Leukemia: Bone marrow cells are mutated and produce abnormal white blood cells (leukocytes)

Front 8

Describe the treatments for two diseases that can be treated using stem cells.

Back 8

Stargardt's disease: Tell healthy human embryonic stem cells to become healthy retinal cells, inject healthy retinal cells into the retina

Leukemia: Chemotherapy/radiation to destroy cancerous bone marrow, obtain stem cells, inject stem cells into bone marrow, stem cells differentiate into healthy bone marrow and produce normal white blood cells

Front 9

What are the seven functions of life?

Back 9

Nutrition, metabolism, growth, response to stimuli, eliminate waste, homeostasis, reproduction

Front 10

What are the three components of the cell theory?

Back 10

1) The cell is the smallest unit of life

2) All living things are made of cells

3) All cells come from other cells

Front 11

What does the surface area of a cell do?

Back 11

The surface area (aka the plasma membrane) allows waste to exit the cell and nutrients to come in

Front 12

What does the volume of a cell do?

Back 12

The volume (everything inside the cell) is what is using nutrients and producing waste

Front 13

What happens as a cell gets larger?

Back 13

As the cell gets larger, the volume increases much faster than the surface area which causes the SA/V ratio to go down, which is not good (too much volume for not enough SA)

Front 14

What are the three sources of stem cells?

Back 14

Embryos produced from therapeutic cloning, umbilical cord blood, adult tissues such as bone marrow

Front 15

What is the formula for finding magnification?

Back 15

Magnification=appear/actual

Front 16

Name the base 10 exponents for centimeters, millimeters, and micrometers

Back 16

Centimeters: 10^-2 m

Millimeters: 10^-3 m

Micrometers: 10^-6 m

Front 17

___________ have a simple cell structure without compartmentalization.

Back 17

Prokaryotes

Front 18

__________ have a compartmentalized cell structure.

Back 18

Eukaryotes

Front 19

True or false: Electron microscopes have a much higher resolution than light microscopes.

Back 19

True

Front 20

How do prokaryotes reproduce?

Back 20

Binary fission

Front 21

What is this a diagram of?

Back 21

A prokaryotic cell

Front 22

What is this a diagram of?

Back 22

A eukaryotic cell

Front 23

What is the function of a cell wall?

Back 23

Support and structure

Front 24

What is the function of the plasma membrane?

Back 24

Controls entry and exit of materials

Front 25

What is the function of pili?

Back 25

Attach to other bacteria for DNA transfer

Front 26

What is the function of cytoplasm?

Back 26

Contains enzymes for metabolic reaction

Front 27

What is the function of the nucleoid?

Back 27

Closed loop of bacterial DNA in a condensed area

Front 28

What is the function of ribosomes?

Back 28

Protein synthesis

Front 29

What is the function of flagellum?

Back 29

Whiplash-like motion causes movement

Front 30

What is the function of the nucleus?

Back 30

holds the DNA

Front 31

What is the function of the rough endoplasmic reticulum?

Back 31

makes proteins that are exported

Front 32

What is the function of mitochondria?

Back 32

cell respiration

Front 33

What is the function of lysosomes?

Back 33

break stuff down

Front 34

What is the function of the golgi apparatus?

Back 34

modifies proteins (from the E.R.)

Front 35

What are the main differences between prokaryotes and eukaryotes?

Back 35

Eukaryote ribosomes are bigger (80S vs. 70S), DNA: prokaryotes have a closed loop of DNA, eukaryotes have linear DNA, prokaryotes don't have compartmentalization and eukaryotes do

Front 36

What is compartmentalization?

Back 36

grouping the molecules responsible for a certain function within a structure

Front 37

What are the main differences between plant and animal cells?

Back 37

Plants cells have a cell wall, animal cells don't

Plant cells have central vacuoles, animal cells don't

Plant cells have chloroplasts, animal cells don't

Front 38

Phospholipids form bilayers in water due to the ___________ properties of phospholipid molecules

Back 38

Amphipathic

Front 39

True or false: Cholesterol is not a component of animal cell membranes.

Back 39

False: Cholesterol is a component of animal cell membranes.

Front 40

What does cholesterol do in mammalian membranes?

Back 40

Cholesterol in mammalian membranes reduces membrane fluidity and permeability to some solutes.

Front 41

What is this a diagram of?

Back 41

The Singer-Nicholson fluid mosaic model of the plasma membrane

Front 42

What was the evidence that led to the proposal of the Davson-Danielli model?

Back 42

Electron micrographs had two dark bands with a light band in the middle

Front 43

What was the evidence that caused the falsification of the Davson-Danielli model and the acceptance of the Singer-Nicholson model?

Back 43

It assumes all membranes are identical, if proteins were exposed to polar on all sides it would be unstable

Front 44

What does it mean for a phospholipid to be amphipathic?

Back 44

Amphipathic phospholipids have hydrophilic and hydrophobic properties.

Front 45

What are three synonyms for hydrophilic?

Back 45

Polar; charged; likes water

Front 46

What are three synonyms for hydrophobic?

Back 46

Non-polar, neutral, dislikes water

Front 47

True or false: In a phospholipid, the phosphate head is hydrophilic and the fatty-acid tails are hydrophobic

Back 47

true

Front 48

What was the Davson-Danielli model?

Back 48

An incorrect model of the plasma membrane that places the phospholipid bilayer within a protein sandwich

Front 49

Why is the Singer-Nicholson model called the fluid mosaic model?

Back 49

Because it is made of many small parts that move sideways

Front 50

What are the functions of integral proteins?

Back 50

Enzymes, pumps, channels

Front 51

What are the functions of peripheral proteins/glycoproteins?

Back 51

Receptors, ID Tags

Front 52

_____________ is a measure of how tightly the solute molecules are packed.

Back 52

Concentration

Front 53

Concentration ________: two areas close to each other have a different concentration.

Back 53

Gradient

Front 54

Describe passive transport.

Back 54

No energy is required. The molecules naturally diffuse across the membrane through phospholipids or channel proteins

Front 55

Describe active transport.

Back 55

The molecule must be forced across the membrane via pumps or vesicles

Front 56

What are the two types of passive transport and what are the main differences between them?

Back 56

1) Simple diffusion, 2) facilitated diffusion

In simple diffusion the molecules can fit between phospholipids (must be small and polar). In facilitated diffusion the molecule requires a specific channel protein (either too big or too polar too fit between fatty acid tails)

Front 57

Define diffusion.

Back 57

The movement of a molecule from high to low without the need for energy (going down it's concentration gradient)

Front 58

Describe vesicle transport, including exocytosis and endocytosis.

Back 58

A vesicle (ball of membrane)carries the molecule to the membrane and releases it (exocytosis) or is formed around the molecule as it enters the cell (endocytosis)

Front 59

Where does the energy for active transport come from?

Back 59

ATP or a previously formed gradient

Front 60

What is one specific example of active transport?

Back 60

Sodium-Potassium Pump: Using ATP, the SPP forces 3 Na+ out and two 2 K+ in

Front 61

Define osmosis.

Back 61

Movement of water from an area of low solute concentration to high solute concentration

Essentially water is moving to spread out the higher concentrated stuff. It is "following the salt"

Front 62

What is another word for concentration?

Back 62

Osmolarity

Front 63

In a(n) __________ solution, the solution has a higher solute concentration than the cell. Water will leave the cell to spread out the solutes

Back 63

Hypertonic

Front 64

In a(n) ________ solution, the solution has the same concentration as the cell.

Back 64

Isotonic

Front 65

In a(n) _________ solution, the solution has too little solute. Water will enter the cell (can burst)

Back 65

Hypotonic

Front 66

Where did the first cells come from?

Back 66

Cell building blocks (amino acids, phospholipids) had to arise spontaneously from inorganic gases

Front 67

Describe the endosymbiotic theory.

Back 67

Eukaryotes arose when a larger prokaryote ate a smaller prokaryote. The smaller prokaryote stayed inside and they reproduced together. Over millions of years, the smaller ones lost some features and became chloroplasts and mitochondria

Front 68

Describe Louis Pasteur's experiment.

Back 68

He boiled broth in an S-necked flask --->no growth

Exposed to air---> microorganisms grow

Front 69

What did Pasteur's experiment disprove?

Back 69

The theory of spontaneous generation

Front 70

What is the theory of spontaneous generation?

Back 70

Life can appear from nothing/ magic

Front 71

What are three theories on where the energy came from to build the first cells?

Back 71

1) cosmic radiation

2)Volcanoes

3) Deep sea hydrothermal vents

Front 72

Where did chloroplasts most likely come from?

Back 72

Photosynthetic bacteria

Front 73

Where did mitochondria most likely come from?

Back 73

Bacteria that could do aerobic respiration (use O2 to break down sugar for energy)

Front 74

What is the evidence for the endosymbiotic theory?

Back 74

1) Mitochondria and chloroplasts have a double membrane (evidence of endocytosis)

2) Mitochondria, chloroplasts, and bacteria are very similar (Similar reproduction [binary fission], have their own DNA, same size ribosomes [70S])

Front 75

What is the evidence for evolution from one ancestor?

Back 75

1) similar biochemistry (things react along similar pathways)

2) Similar structures

3)Same genetic code: same DNA (64 codons) gives the same proteins (amino acid sequence) in all organisms

Front 76

What are some exceptions to the evidence for evolution from one ancestor?

Back 76

Mitochondria, some bacteria have less STOP codons (appropriated for amino acids instead)

Front 77

_______ is division of the nucleus into two genetically identical daughter nuclei.

Back 77

Mitosis

Front 78

Describe the three phases of the cell cycle.

Back 78

1) Interphase- cell performs normal functions

2) Mitosis- division of the nucleus

3) Cytokinesis- division of the cell

Front 79

Describe the three phases of interphase.

Back 79

G1: normal cell functions, reproduction of organelles

S: DNA Replication

G2: Critical checkpoints to make sure it's a good time to divide (is there enough space? nutrients? etc.)

Front 80

What percent of its life cycle does the cell spend in interphase?

Back 80

90%

Front 81

What is the difference between chromatin and chromosomes?

Back 81

Chromosomes are supercoiled chromatin

Front 82

What are the four phases of mitosis?

Back 82

Prophase, metaphase, anaphase, telophase

Front 83

What happens during prophase?

Back 83

1) chromatin condenses into chromosomes, 2) centrioles move to the poles, 3) spindle microtubules are formed, 4) nuclear membranes dissolve

Front 84

What happens during metaphase?

Back 84

1) Spindle microtubules attach at centromeres, one on each side, 2) chromosomes are aligned down the middle

Front 85

What happens during anaphase?

Back 85

Sister chromatids are pulled apart to opposite poles of the cell

Front 86

What happens during telophase?

Back 86

Undoes all the things from prophase.

1) Chromosomes uncoil into chromatin, 2) Centrioles leave the poles, 3) spindle microtubules dissolve, 4) nuclear membranes form

Front 87

What happens during cytokinesis?

Back 87

One cell divides into two cells

Front 88

Describe the difference between cytokinesis in animal and plant cells.

Back 88

Animal cells: cytokinesis begins with the formation of a cleavage furrow

Plant cells: cytokinesis begins with the formation of the cell plate

Front 89

Proteins called _______ are responsible for regulating the cell cycle

Back 89

Cyclins

Front 90

What is cancer?

Back 90

Uncontrolled cell division

Front 91

What is a mutagen?

Back 91

An agent that causes mutations (change in DNA)

Front 92

What are oncogenes?

Back 92

A gene that, if mutated or overexpressed, can cause cancer

Front 93

What is a primary tumor?

Back 93

The first site of uncontrolled cell division

Front 94

What is metastasis?

Back 94

A piece of primary tumor breaks off and travels through the blood stream, can form secondary tumors.