Chapter 5 Flashcards
1
Q
When was the word cell first used to refer to the microscopic units of life
A
1665 by British scientist Robert Hooke while he was looking at cork under a microscope
2
Q
Who was the first person to observe cells?
A
Anton Van Leeuwenhoek
3
Q
What is cell theory and who made it?
A
Theodor Schwann and Matthias Jakob Schleiden, to propose that cells are the basic building blocks of all living things. Around 1850, a German doctor named Rudolf Virchow was studying cells under a microscope when he happened to see them dividing and forming new cells. He realized that living cells produce new cells through division. Based on this realization, Virchow proposed that living cells arise only from other living cells.
The ideas of all three scientists — Schwann, Schleiden, and Virchow — led to cell theory, which is one of the fundamental theories unifying all of biology. Cell theory states that:
All organisms are made of one or more cells.
All the life functions of organisms occur within cells.
All cells come from already existing cells.
4
Q
What is cell theory and who made it? (simple version)
A
Idea: All organisms are made of one or more cells, all cells come from existing cells, and all th life functions of organisms occur within the cell.
People: Theodor Schwann, Matthias Jakob Schleiden, and Rudolf Virchow.
5
Q
Milestone in Microscope development:
A
Leeuwenhoek made his own microscope lenses that were very powerful.
1800’s light microscopes reach their limit.
1950’s electron microscope is created and spawns the field of molecular biology
6
Q
What are the 4 structure shared by all cells?
A
Plasma membrane, cytoplasm, Ribosomes, and DNA
7
Q
What is the plasma membrane?
A
a thin coat of lipids that surrounds a cell. It forms the physical boundary between the cell and its environment, so you can think of it as the “skin” of the cell.
8
Q
Cytoplasm
A
Cytoplasm refers to all of the cellular material inside the plasma membrane. Cytoplasm is made up of a watery substance called cytosol and contains other cell structures such as ribosomes.
9
Q
Ribosomes
A
Ribosomesare structures in the cytoplasm where proteins are made.
10
Q
DNA
A
DNAis a nucleic acid found in cells. It contains the genetic instructions that cells need to make proteins.
11
Q
Plasma Membrane
A
Theplasma membrane(also called the cell membrane) is a thin coat of lipids that surrounds a cell. It forms the physical boundary between the cell and its environment, so you can think of it as the “skin” of the cell.
12
Q
Why are cells tiny?
A
To carry out life processes, a cell must be able to quickly pass substances into and out of the cell.
Anything that enters or leaves a cell must cross its outer surface. Itis this need to pass substances across the surface that limits how large a cell can be.
13
Q
What is the nucleus of a cell?
A
A structure in the cytoplasm that is surrounded by a membrane (the nuclear membrane) and contains DNA.
Based on whether or not they have a nucleus, there are two basic types of cells: prokaryotic cells and eukaryotic cells.
14
Q
What is a prokaryotic cell?
A
Cells without a nucleus
15
Q
What type of organisms are prokaryotic cells found in?
A
SIngle-celled organisms.
The DNA is in the cytoplasm instead of a nucleus.
16
Q
What are Eukaryotic cells?
A
Cells that contain a nucleus.
17
Q
What are organisms with eukaryotic cells called?
A
Eukaryotes
18
Q
What do eukaryotic cells contain beside a nucleus?
A
Organelles.
19
Q
What is an organelle?
A
A structure within the cytoplasm that performs a specific function for the cell.
20
Q
What is a mitochondria?
A
An organelle that provides energy to the cell?
21
Q
What is a vacuole?
A
An organelle that stores substances in the cell.
22
Q
Who can carry out more functions? Eukaryotes or Prokaryotes?
A
Eukaryotes because they have organelles to do jobs for them.
23
Q
What is the correlation ebtween cell shape and cell function?
A
Cell shape impacts cell function and perhaps vice versa?
24
Q
What is the Plasma Membrane?
A
A structure that forms a barrier between the cytoplasm inside the cell and the environment outside the cell.
25
What are the functions of the plasma membrane?
-Protect and support the cell
-Control everything that enters and leaves cell
-Some may have extensions like flagella or cilia that can help the cell to move OR sweep foreign particles
26
What is the cell membrane made of?
Mainly Phospholipid Bilayer
Phospholipids are made of fatty acids and alcohol
Consists of 2 layers of phospholipids: 1 layer is water loving (hydrophilic), and 1 layer is water hating (hydrophobic)
27
What is the cell membrane made of besides phospholipids
Mainly proteins and lipids. Some sugars too.
28
What is another good reason to not smoke?
Smoking can have devastating effects on the body's ability to protect itself from repeated, serious respiratory infections, such as bronchitis and pneumonia.
29
What are Cilia?
Micro-hairs that ling the respiratory, reproductive, and digestive systems. They trap and remove dust, germs, and other foreign particles.
30
What is cytoplasm?
(Think of a plastic bag filled with jello)
A thick (usually) colorless SOLUTION that fills each cell and is enclosed by the cell membrane.
The cytoplasm houses all of the organelles
31
What is nucleoplasm?
Watery substance found in the nuclei of eukaryotic cells
32
What is cytosol?
The liquid part of the cytoplasm that surrounds the organelles
It is composed of about 80 percent water and also contains dissolved salts, fatty acids, sugars, amino acids, and proteins such as enzymes. These dissolved substances are needed to keep the cell alive and carry out metabolic processes. For example, enzymes dissolved in cytosol break down larger molecules into smaller products that can then be used by organelles of the cell. Waste products are also dissolved in the cytosol before they are taken in by vacuoles or expelled from the cell.
33
KNow this about Prokaryotic cells
Though prokaryotic cells do not have organelles (they do have ribosomes), they still have cytoplasm. It is within the cytoplasm that most cellular activities occur, including the many metabolic pathways that occur within organelles, such as photosynthesis and aerobic respiration.
34
What is a cytoskeleton?
A framework of protein scaffolds that structures the cytoplasm and the cell
35
What are 3 main kinds of cytoskeleton fibers? (simple version?
microtubules, intermediate filaments, and microfilaments.
36
What are microtubules?
Microtubules, are the thickest of the cytoskeleton structures. They are most commonly made of filaments which are polymers of alpha and beta tubulin, and radiate outwards from an area near the nucleus called the centrosome. Tubulin is the protein that forms microtubules. Two forms of tubulin, alpha and beta, form dimers (pairs) which come together to form the hollow cylinders. The cylinders are twisted around each other to form the microtubules. Microtubules help the cell keep its shape. They hold organelles in place and allow them to move around the cell, and they form the mitotic spindle during cell division. Microtubules also make up parts of cilia and flagella, the organelles that help a cell move.
37
What are microfilaments?
Microfilaments, are made of two thin actin chains that are twisted around one another. Microfilaments are mostly concentrated just beneath the cell membrane, where they support the cell and help the cell keep its shape. Microfilaments form cytoplasmatic extentions, such as pseudopodia and microvilli, which allow certain cells to move. The actin of the microfilaments interacts with the protein myosin to cause contraction in muscle cells. Microfilaments are found in almost every cell, and are numerous in muscle cells and in cells that move by changing shape, such as phagocytes (white blood cells that search the body for bacteria and other invaders).
38
What are intermediate filaments?
Intermediate filaments differ in make-up from one cell type to another. Intermediate filaments organize the inside structure of the cell by holding organelles and providing strength. They are also structural components of the nuclear envelope. Intermediate filaments made of the protein keratin are found in skin, hair, and nails cells.
39
Cells will go _____ if they do not get enough nutrients.
Dormant
40
What are microtubules? (Simple version)
Microtubules are the thickest of the cytoskeleton structures and are most commonly made of filaments which are polymers of alpha and beta tubulin.
41
What are microfilamens (Simple Version)
Microfilament are the thinnest of the cytoskeleton structures and are made of two thin actin chains that are twisted around one another.
42
What is a ribosome?
A cell that synthesizes proteins
43
What are some organelles in animal (Eukaryotic) cells?
Organelles in animal cells include the nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, vesicles, and vacuoles. Ribosomes are not enclosed within a membrane but are still commonly referred to as organelles in eukaryotic cells
44
SOme stuff about the nucleus:
-Largest organelle in a eukaryotic cell
-contains most of cell's DNA
-regulates gene expression
-controls protein the cell makes
-contains nucleoplasm
-some cells have no nucleus
-some cells have multiple nuclei
45
What is the nuclear envelope?
The membrane that encloses the nucleus.
It has tiny holes called nuclear pores which let proteins and RNA molecules in and out.
46
What is a mitochondria?
The powerhouse of the cell.
Uses energy from organic molecules like glucose to make ATP!!!!!
47
What are the 5 compartments of the Mitochondria?
1. The outer mitochondrial mebrane
2. The intermembrane space (space between inner and outer membranes)
3. The inner mitochondrial membrane
4. The cristae (formed by infoldings of the inner membrane)
5, the matrix (sace within the inner membrane
48
What are the 5 layers of the mitochondria involved in?
cellular respiration
49
What is endosymbiotic theory?
An evolutionary theory that thinks mitochondria were once free living organisms, but eventually got absorbed into prokaryotic cells.
50
What does ER stand for in biology?
Endoplasmic Reticulum
51
What is Endoplasmic Reticulum?
a network of phospholipid membranes that form hollow tubes, flattened sheets, and round sacs.
These are called cisternae
52
What are the 2 major functions of the ER?
Transport and Synthesis
53
What are transport and synthesis in terms of the ER?
Transport: Molecules, such as proteins, can move from place to place inside the ER, much like on an intracellular highway.
Synthesis: Ribosomes that are attached to ER, similar to unattached ribosomes, make proteins. Lipids are also produced in the ER.
54
What are te 2 types of ER?
rough endoplasmic reticulum (RER)
and smooth endoplasmic reticulum (SER)
55
What are RER and SER?
Rough endoplasmic reticulum is studded with ribosomes, which gives it a “rough” appearance. These ribosomes make proteins that are then transported from the ER in small sacs called transport vesicles. The transport vesicles pinch off the ends of the ER. The rough endoplasmic reticulum works with the Golgi apparatus to move new proteins to their proper destinations in the cell. The membrane of the RER is continuous with the outer layer of the nuclear envelope.
Smooth endoplasmic reticulum does not have any ribosomes attached to it, and so it has a smooth appearance. SER has many different functions, some of which include lipid synthesis, calcium ion storage, and drug detoxification. Smooth endoplasmic reticulum is found in both animal and plant cells and it serves different functions in each. The SER is made up of tubules and vesicles that branch out to form a network. In some cells there are dilated areas like the sacs of RER. Smooth endoplasmic reticulum and RER form an interconnected network.
56
What is the Golgi apparatus?
A large organelle that processes proteins and prepares them for use both inside and outside the cell.
57
How did the Golgi apparatus get its name?
It was discovered in 1898 by Italia physician Camillo Golgi
58
What is the Golgi apparatus made of?
The Golgi apparatus is usually made up of five to eight cup-shaped, membrane-covered stacks of discs called cisternae (singular, cisterna)
a typical mammalian cell will have 40-80 stacks.
while plant cells can have up to several hundred golgi stacks scattered throughout the cytoplasm.
59
Golgi Apparatus (COmplex version)
The Golgi apparatus modifies, sorts, and packages different substances for secretion out of the cell, or for use within the cell. The Golgi apparatus is found close to the nucleus of the cell where it modifies proteins that have been delivered in transport vesicles from the RER. It is also involved in the transport of lipids around the cell. Pieces of the Golgi membrane pinch off to form vesicles that transport molecules around the cell. The Golgi apparatus can be thought of as similar to a post office; it packages and labels "items" and then sends them to different parts of the cell. The Golgi apparatus tends to be larger and more numerous in cells that synthesize and secrete large quantities of materials; for example, the plasma B cells and the antibody-secreting cells of the immune system have prominent Golgi complexes.
60
Golgi apparatus (simple version)
Its like a post office that sorts, packages, and ships cells
61
What are veicles and vacuoles? (simple
vesicles and vacuoles are sac-like organelles that store and transport materials in the cell. Vesicles are much smaller than vacuoles and have a variety of functions
62
What are some OTHER vesicles?
Lysosomes, which use enzymes to break down foreign matter and dead cells.
Peroxisomes, which use oxygen to break down poisons.
transport vesicles, transport contents between organelle as well as between cell exterior and interior.
63
What are centrioles?
Organelles involved in cell division.
They organize chroosomes before cell division so that each daughter cell has the correct number of chromosomes after the cell divides.
Centrioles are found only in animals.
Centrioles are cylindrical in shape.
64
What does the plasma mebrane do?
Transports things in and out of the cell
65
What are the 2 BASIC ways which a cell can cross the plasma membrane?
Passive transport and ACtive transport
66
What are passive and active transport?
passive transport requires no energy
while active transport requires energy
67
What is one important rule about solutes?
solution.The more particles of a solute in a given volume, the higher the concentration. The particles of solute always moves from an area where it is more concentrated to an area where it is less concentrated. It’s a little like a ball rolling down a hill. It goes by itself without any input of extra energy.
68
What ae the 2 types of passive transport?
Simple diffusion and facilitated diffusion
69
What are simple and facilitated diffusion?
2 types of passive transport.
Simple diffusion: the net movement of molecules from an area of greater concentration to an area of lesser concentration
70
What are DYnamic equilibrium and concentration gradient?
Many things can diffuse. Odors diffuse through the air, salt diffuses through water and nutrients diffuse from the blood to the body tissues. This spread of particles through random motion from an area of high concentration to an area of lower concentration is known as diffusion. This unequal distribution of molecules is called a concentration gradient. Once the molecules become uniformly distributed, dynamic equilibrium exists. The equilibrium is said to be dynamic because molecules continue to move, but despite this change, there is no net change in concentration over time. Both living and nonliving systems experience the process of diffusion. In living systems, diffusion is responsible for the movement of a large number of substances, such as gases and small uncharged molecules, into and out of cells.
71
What is Osmosis?
a specific type of diffusion. This refers to the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low water concentration.
72
What are semi-permeable membranes?
Very thin layers of material which allow some things to pass through them, but prevent other things from passing through
73
There are three possible relationships that cells can encounter when placed into a sugar solution. What are they?
The concentration of solute in the solution can be equal to the concentration of solute in cells. In this situation the cell is in an isotonic solution (iso = equal or the same as normal). A red blood cell will retain its normal shape in this environment as the amount of water entering the cell is the same as the amount leaving the cell.
2. The concentration of solute in the solution can be greater than the concentration of solute in the cells. This cell is described as being in a hypertonic solution (hyper = greater than normal). In this situation, a red blood will appear to shrink as the water flows out of the cell and into the surrounding environment.
3. The concentration of solute in the solution can be less than the concentration of solute in the cells. This cell is in a hypotonic solution (hypo = less than normal). A red blood cell in this environment will become visibly swollen and potentially rupture as water rushes into the cell.
74
What is facilitated diffusion?
Diffusion that happens with the help of transport proteins.
75
What are transport proteins?
Special proteins that aid the diffusion process.
Channel proteins form pores, or tiny holes, in the membrane. This allows water molecules and small ions to pass through the membrane without coming into contact with the hydrophobic tails of the lipid molecules in the interior of the membrane.
Carrier proteins bind with specific ions or molecules, and in doing so, they change shape. As carrier proteins change shape, they carry the ions or molecules across the membrane
76
What is Active Transport?
When cells require energy to move from an area of low concentration to an area of higher concentration this is considered active transport.
77
What powers Active Transport?
ATP
78
What is the Sodim-Potassium Pump?
A mechanism of active transport that moves sodium ions out of the cell and potassium ions into the cell
79
What is the role of sodium and potassium in the body?
Both are essential dietary minerals, meaning you have to obtain them in the foods you eat. Both sodium and potassium are also electrolytes, meaning that they dissociate into ions (charged particles) in solution, which allows them to conduct electricity. Normal body functions require a very narrow range of concentrations of sodium and potassium ions in body fluids, both inside and outside of cells.
Sodium is the principal ion in the fluid outside of cells. Normal sodium concentrations are about 10 times higher outside than inside of cells.
Potassium is the principal ion in the fluid inside of cells. Normal potassium concentrations are about 30 times higher inside than outside of cells.
80
The differences in potassium and sodium concentration do what?
They create an electrical gradient across the cell membrane, called membrane potential. Tightly controlling membrane potential is critical for vital body functions, including the transmission of nerve impulses and contraction of muscles.
81
What is vesicle transport?
Some molecules are too big to pass through plasma membrane, so they need help from vesicle transport. This requires energy.
82
What are the 2 types of vesicle transport?
Endocytosis
Exocytosis
83
What is endocytosis?
MOves substance ito cell. Plasma membrane engulfs substance and vesicle pinches off membrane and carries it into the cell.
84
What is Exocytosis?
A type of vesicle transport that moves a substance out of the cell.
85
What is homeostasis?
The process of maintaining stable conditions inside a cell (or an entire organism).
86
How much sodium and potassium should I eat?
Total sodium intake should be less than 2300 mg/day. Most salt in the diet is found in processed foods or added with a salt shaker. Stop adding salt and start checking food labels for sodium content. Foods considered low in sodium have less than 140 mg/serving (or 5% daily value).
Total potassium intake should be 4700 mg/day. It's easy to add potassium to the diet by choosing the right foods, and there are plenty of choices. Most fruits and vegetables are high in potassium, but especially potatoes, bananas, oranges, apricots, plums, leafy greens, tomatoes, lima beans, and avocado. Other foods with substantial amounts of potassium are fish, meat, poultry, and whole grains.
87
What is cellular respiration? (simple)
Cells of living things get energy by "burning" glucose in the process called cellular respiration
88
Where do organisms get energy from?
Food.
Food consists of organic molecules that store energy in their chemical bonds.
89
What is the chemical formula for glucose?
C6H12O6
90
What can an ATP molecule be likened to?
A rechargeable battery
91
How much energy does it cost to do your body’s work?
A single cell uses about 10 million ATP molecules per second, and recycles all of its ATP molecules about every 20-30 seconds
92
What is cellular respiration?
The proces sby which living cells break down glucose molecules and release energy.
93
What is the chemical equation for cellular respiration?
C6H12O6 + 6O2 → 6CO2 + 6H2O + Chemical Energy (in ATP)
94
What are the 3 stages of cellular respiration?
Glycolysis, the Krebs cycle, and electron transport.
95
What is Glycolysis?
The word glycolysis means “glucose splitting,” which is exactly what happens in this stage. Enzymes split a molecule of glucose into two molecules of pyruvate (also known as pyruvic acid). This occurs in several steps.
96
What is the Krebs cycle?
Recall that glycolysis produces two molecules of pyruvate (pyruvic acid). These molecules enter the matrix of a mitochondrion, where they start the KREBS (also known as the citric acid cycle).
The second stage of cellular respiration, called the Krebs cycle, takes place in the matrix of a mitochondrion. During this stage, two turns through the cycle result in all of the carbon atoms from the two pyruvate molecules forming carbon dioxide and the energy from their chemical bonds being stored in a total of 16 energy-carrying molecules (including 4 from glycolysis).
97
What is ultimately produced from one glucose molecule during cellular respiration?
You have seen how the three stages of aerobic respiration use the energy in glucose to make ATP. How much ATP is produced in all three stages combined? Glycolysis produces 2 ATP molecules, and the Krebs cycle produces 2 more. Electron transport begins with several molecules of NADH and FADH2 from the Krebs cycle and transfers their energy into as many as 32 more ATP molecules. All told, then, up to 36 molecules of ATP can be produced from just one molecule of glucose in the process of cellular respiration.
98
What is the third stage of circular respiration?
The third and final stage of cellular respiration, called electron transport, takes place on the inner membrane of the mitochondrion. Electrons are transported from molecule to molecule down an electron-transport chain. Some of the energy from the electrons is used to pump hydrogen ions across the membrane, creating an electrochemical gradient that drives the synthesis of many more molecules of ATP.
99
When sprinting, what process is being used to generate energy?
An anaerobic process that makes energy from glucose without using oxygen. This is called anaerobic respiration.
100
What are the 2 types of fermentation?
Alcoholic fermentation and lactic acid fermentation.
101
notice that your muscles start to feel a burning sensation?
This may occur when your muscle cells use lactic acid fermentation to provide ATP for energy. The buildup of lactic acid in the muscles causes the feeling of burning. The painful sensation is useful if it gets you to stop overworking your muscles and allow them a recovery period during which cells can eliminate the lactic acid.
102
Pos and cons of anaerobic respiration?
With oxygen, organisms can use aerobic cellular respiration to produce up to 36 molecules of ATP from just one molecule of glucose. Without oxygen, organisms must use anaerobic respiration to produce ATP, and this process produces only two molecules of ATP per molecule of glucose. Although anaerobic respiration produces less ATP, it has the advantage of doing so very quickly. It allows your muscles, for example, to get the energy they need for short bursts of intense activity. Aerobic cellular respiration, in contrast, produces ATP more slowly.
103
What is alcoholic fermentation?
Alcoholic fermentation is carried out by single-celled organisms including yeasts and some bacteria. We use alcoholic fermentation in these organisms to make biofuels, bread, and wine.
104
What is lactic acid fermentation?
Lactic acid fermentation is undertaken by certain bacteria, including the bacteria in yogurt, and also by our muscle cells when they are worked hard and fast.
