BIOL1997 Flashcards
Module 3 (148 cards)
1
Q
What are examples of micronutrients?
A
- Vitamins
- Minerals
2
Q
What are examples of macronutrients?
A
- Carbs
- Proteins
- Fats
3
Q
What is the similarity and difference between protein and carbohydates?
A
o Similarity: Made out of monomers joined together to make a polymer
o Contrast: Carbohydrates have branches while proteins don’t
4
Q
What does anabolic mean?
A
• Anabolic- building up
o Small molecules are assembled into large ones. Energy is required. Consumes ATP.
-Often intermediates
5
Q
What does catabolic mean?
A
• Catabolic- breaking down
o Large molecules are broken down into small ones. Energy is released. Releases ATP.
-Often have intermediates
6
Q
Where is glycogen, a carbohydrate, stored?
A
• Glycogen is stored in many cells, especially in the liver and skeletal muscle
7
Q
What are proteins made of?
A
Amino acids
8
Q
How many essential amino acids are there?
A
9
9
Q
How many non-essential amino acids are there?
A
11
10
Q
What is the general structure of amino acids?
A
A basic amino group, which at the pH of the cell, gains a proton and becomes –NH3+
An acidic carboxyl group, which at the pH of the cell, donates a proton and becomes –COO-
A variety of different side chain groups, abbreviated as R.
11
Q
Do proteins need to get replaced?
A
Yes
12
Q
What happens when proteins are damaged?
A
o Damaged proteins are broken down for recycling and new ones produced to replace them
13
Q
How do proteins go through the cell from the ribosome?
A
o Protein has to stay unfolded to go through the cell so that it is able to go through the cell in a streamlined manner
o Hsp70 proteins are unraveled and linear so they can go to their needed point
o Hsp70 proteins go away and the protein can be correctly folded
o Happens near the nucleus
14
Q
What is unsaturated fat?
A
o Unsaturated –when there is a double bond between the carbons
Double bond in unsaturated fatty acids is in a cis configuration, causing a ‘kink’ in the structure of the fatty acid chain
15
Q
What is unsaturated fat?
A
o Saturated fatty acids- fatty acid chains that contain only carbon-carbon single bonds
Unsaturated fats is less destructive –> less capable of build fat up beneath arteries
16
Q
What is fat made of?
A
Glycerol (one hydroxyl group per carbon) made of a carbon backbone, to which fatty acids (OH-C=O) are attached to make tryglicerides
17
Q
How is fat transported through the blood?
A
Triglycerides coated in lipoproteins so they are no longer hydrophobic
18
Q
Where is fat stored?
A
Adipose tissue, which can expand, grow and divide
19
Q
What are lipids?
A
A diverse group of biomolecules including fats.
Defined as substances that can be extracted from biological materials using non-polar (hydrophobic) organic solvents
20
Q
What are lipids made of?
A
Carbon, hydrogen and oxygen and have hydrophobic structures
21
Q
Where are lipids stored?
A
Under epithelial of veins
22
Q
How can ATP power cellular processes?
A
o Phosphate groups have high potential energy
o First phosphate is called alpha, second one beta and the last one gamma.
- Phosphates at the end of ATP have negative charges on them
- Last phosphate put on protein
- Negative charge of the gamma phosphate opens proteins up as it destroys negative-positive attractions of the proteins by binding to the proteins positive side and henceforth making the negatively charged parts repel from each other
- When an enzyme takes that away, the protein closes up again as negative charge is taken away
23
Q
What is the general composition of the body?
A
o Liquid – 60% Infant- 70% Elderly person- 50~55% o Protein- 18% o Fat- 16% o Carbohydrates, Minerals, etc.-6%
24
Q
What three macromolecules are convertible into each other?
A
Fats, proteins and carbohydrates
25
When you eat protein food, will you absorb the protein or will something else happen?
o Your body will break down into amino acids or dipeptides (rare anything bigger)
o Mainly absorbs amino acid
o Vilus have evolved to increase surface area so can get more amino acids into bloodstream
26
Where do animals have to get their essential amino acids from?
Plants- animals can't make them themselves
27
Are carbs often converted into fat? Why?
Yes, because not a lot of space to store carbs
28
How are proteins, fats and carbohydrates interconverted?
Through glycolysis and the Kreb's cycle
29
What are the 4 different types of tissues?
- Connective
- Muscle
- Nervous
- Epithilium
30
What are 3 examples of specialization and complex functions?
```
o Endocrine cells that can respond to homeostatic signals and release hormones
Endocrine- no duct
• Secretes hormones
Exocrine - duct
o Voluntary muscle
o Fibroblasts that can repair wounds
```
31
Where exactly does mRNA get translated?
mRNA comes out of nuclear pores and gets translated in endoplasmic reticulum if the ribosomes are bound to the rough endoplasmic reticulum or free in the cytoplasm.
32
What is the difference between plant and animal cells?
```
Animal cell-
Animal cells do not have chloroplasts
Don’t have plastids
Small vacuoles
Don’t have a cell wall
```
Plant cell-
Plant cells have a cell wall
Have plastids
Large vacuoles
33
Describe the structure of the cell membrane
-Fluid mosaic structures that are composed of phospholipid bilayer containing proteins, glycoproteins and glycolipids
34
Describe the function of the cell membrane
- Separates cell from environment
- Regulates the passage of molecules in and out of cell to maintain cell integrity
- Selectively permeable
35
What is the function of the cytoplasm?
Acts as a medium where various organelles can remain suspended at their proper places
-Many chemical reactions take place in the cytoplasm
36
What is the function and structure of the nucleus?
It stores the information needed to control all cell activities.
The pores allow regulate the passage of substances (such as RNA and proteins) between the nucleus and the cytoplasm.
The nucleoplasm is liquid background in the nucleus where chromatin (made up of protein and nucleic acid) is found. The chromatin material also separates into chromosomes.
Nucleolus is a dense, granular region and contains a large amount of nucleic acid (mostly RNA) The nucleolus is responsible for the manufacture of ribosomes.
37
What is the structure of the plastid?
- Surrounded by a double membrane envelope and contains multiple copies of circular DNA, plus RNA and small ribosomes. Outer membrane high permeable to ions and smal molecules
- Inner membrane more selective contianing carrier proteins responsible for transporting molecules into and out of plastid
- Matrix enclosed within the inner membrane of a plastid is the stroma
38
What is the function of the plastid?
-Provide the cell with energy and sugars, and synthesises amino acids and most of a cell’s fatty acids.
39
What is the structure of the chloroplast?
Surrounded by double membrane which allows substances to pass between cytoplasm and chloroplast
Contains chlorophyll and thylakoids (parts of the membrane that form flattened disc-like sacs)
The layering of the membranes increases the surface area over which chlorophyll occurs, allowing a large amount of sunlight to be absorbed for the process of photosynthesis.
Photosynthetic pigments and enzymes are assembled on internal thykaloid membranes
40
What is the function of the chloroplast?
- Carry out photosynthesis
| - Chloroplasts (a type of plastid) are responsible for the capture of energy from light during photosynthesis
41
What is the structure of the vacuole?
Consists of cell sap (watery solution) surrounded by a membrane called tonoplast.
Contains hydrolytic enzymes
42
What is the function of the vacuole?
- Place where nutrients, pigments or waste materials
- Helps cell keep its structure (maintains cell turgor pressure)
- Many of the functions that are carried out by animal cell lysosomes occur in one or more large membrane-bound vacuoles (serves as degradative compartment)
43
What is the structure and function of the cell wall?
Made of long strands of cellulose, lignin and pectin and support the structure of an organism, protect the cell and form a bridge to adjacent cells
- Rigidity and strength: allows plant to grow tall and hold out their leaves to capture light
- Physical barrier:protection
- Maintains shape and structure of cell
44
What is the structure of the cytoskeleton?
Network of tiny microbutules and microfilaments and intermediate filaments
- Microfilaments: composed of protein actin
- Microtubules: composed of tubulin
- Intermediate filaments: variable in structure and made of various proteins
45
What is the function of the cytoskeleton?
-Keeps organelles in place or move individual organelles or the whole cytoplasm from one place to another
-Facilitate maintenance and remodelling of cell shape
-Microfilaments contribute to structural organisation of cells and facilitate intracellular movement
Microtubules: dynamic scaffolding elements in eukaryotic cells
Intermediate filaments: strong, stable and resist stretching, and provide mechanical support
46
What is the structure of the microbodies?
- Spherical to sausaged shaped with homogenous, granular contents and sometimes crystalline inclusions.
- Surrounded by a sngle membrane, contain a variety of degradative enzymes (such as catalase)
47
What is the function of the microbodies?
-Main organelle involved in removal of compounds generated within cells
-Peroxisomes oxidise amino acids and uric acids
Glyoxysomes are involved in conversion of fatty acids to sugars
48
What is the structure of the mitochondria?
Outer membrane of double membrane gives mitochondria its shape and allows the passage of small substances into and out of mitochondria. Very permeable.
Inner membrane of double membrane is folded into cristae which increases the area for the attachment of groups of enzymes responsible for making energy for the cell. Highly impermeable
Central space in a mitochondrion is filled with fluid and is termed matrix which contains mitochondrial DNA and enzymes.
49
What is the function of the mitochondria?
- Produce energy by chemical respiration
| - Released energy is stored in molecules of ATP which are used by cells to drive a vast range of chemical reactions.
50
What is the structure of the lysosomes?
Membrane bound organelles of animal cells involved in the degradation of many types of macromolecules.
Vesicle is filled with digestive enzymes for intercellular digestion
51
What is the function of the lysosomes?
Break down material ingested from outside the cell via endocytosis or phagocytosis
- Degrade worn out organelles via autophagy
- Allows macromolecules to be broken down to their constituent amino acids, sugars and nucleotides for reuse and secretion.
52
What is the structure of golgi bodies?
Consists of stacks of 4 to 10 disc-shaped cisternae and are surrounded by a cloud of small vesicles.
53
What is the function of golgi bodies?
-Secretory function. -Also
Processes, packages and sort cell products.
-Protein and glycoproteins enter each Golgi stack at the cis face and go through the body
-One mature products reach the trans face of the stack, they must be sorted and targeted to their correct destinations.
-Involved in the processing and packaging of glycoproteins and polysaccharides
54
What is the function of the transport vesicles?
Formed by Golgi apparatus move to and fuse with plasma membrane, and thereby release their contents to the outside of the cell in a process termed exocytosis and contents are taken up by endocytosis
-Small vesicles transport membrane and luminal contents between the ER, Golgi apparatus, endosomes, lysosomes, vacuoles and cell surface
55
What is the structure of the endoplasmic reticulum?
Network of membranous sacs (cisternae) that extends throughout the cytoplasm of eukaryotic cells
Smooth ER is the main site for lipid production, essential for membrane repair and manufacture.
Rough ER has ribosomes bound to its surface and folds/ processes protein products made by the cell.
56
What is the function of the endoplasmic reticulum?
Provides a connection of pathways between the nucleus and the cell’s environment allowing intracellular transport. However, it can also process cell products.
Involved in protein and lipid synthesis, and in detoxification of harmful compounds
57
What is the structure of ribosomes?
- Composed of two subunits, each of which is assembled in the nucleolus from RNA and protein molecules
- Subunits move through nuclear pores into the cytosol, where they associate with an mRNA molecule, forming a functional ribosome that facilitate protein synthesis.
58
What is the function of the ribosome?
Function is protein synthesis
59
What makes a prokaryotic cell and what are some examples of this?
o No membrane bound organelles
o Single cell
o Cell wall made of carbohydrates
o Don’t reproduce sexually to another cell
Use pilus to join to another cell and pull their cell membrane close, where they swap plasmids (genetic information)
o Bacteria- peptidoglycan (sugar and amino acid lattice) major constituent of cell wall
o Archaea- do not have peptidoglycan as major constituent of cell wall, often live in extreme conditions like anoxic mud, petroleum deposits and hot temperatures
60
what are examples of eukaryotes and what is a eukaryotic cell?
```
o Membrane bound organelles
o Fungi doesn’t have chloroplasts --> not autotrophic
o Eukaryotes include:
Protists
Fungi
Pants
Animals
```
61
Describe bacteria structure
-Unicellular
-Cells don’t have nuclei or membrane bound organelles
-Distinctive cell walls
-Autotrophs/
Heterotrophs
62
Describe archaea structure
-Unicellular
-Cells lack nuclei and membrane bound organelles
-Distinctive cell walls
-Autotrophs
/Heterotrophs
-Unlike bacteria, composed of glycerol-ether lipids
63
Describe protista structure
-Unicellular or multicellular
-Cells with nuclei and membrane bound organelles
-Some have cell walls
-Autotrophs/
Heterotrophs
64
Describe plantae structure
- Multicellular
- Cells with nuclei and membrane bound organelles
- Cell walls of cellulose
- Autotrophs
- Complex organ systems
- Plants get energy from the sun
65
Describe fungi structure
- Most are multicellular thread-like hyphae
- Cells with nuclei and membrane bound organelles
- Cell walls of chitin
- Fungi absorb molecules from the environment
66
Describe animalia structure
- Multicellular
- Cells with nuclei and membrane bound organelles
- No cell walls
- Heterotroph
- Complex organ systems
- Animals ingest other organisms
67
Describe the composition of lipid bilayer cell membranes
* The phospholipid bilayer is made of hydrophilic heads and hydrophobic tails
* In water, phospholipid molecules aggregate and align themselves so that the polar heads face outwards and interact with the polar water molecules
* The hydrophobic tails cluster together, away from contact with the water molecules
68
What is glycocalyx?
o Layer of carbohydrates on top of membrane
o Got a lot of charge
o Gives more 3 dimensional aspects
69
What does ampithatic mean?
o It is ampithatic- both hydrophobic and hydrophilic parts
| Hydrophobic tail- double bond forms a kink when fatty acid tail is unsaturated
70
Are phospholipids ampithatic?
Yes
71
Draw a phospholipid
Diagram in notes
72
What is the role of cholesterol in the phospholipid membrane?
Cholesterol reinforces membrane
73
What is cholesterol?
| Draw structure of cholesterol
Cholesterol is not fat, but is lipid
o Branched part at the end of the structure drops off and becomes a precursor to steroid hormones
o –OH is hydrophilic part while the rest is hydrophobic
Amphipathic molecule
O points towards hydrophilic heads outside the membrane
74
What are the types of proteins and glycoproteins in the phospholipid bilayer?
o Channels or carriers
o Peripheral proteins- loosely associated with membrane surface by non-covalent interactions
o Integral membrane proteins- interact with the inner hydrophobic regions of the membrane, sometimes through covalent bonding to fatty acid chains or lipid molecules within the membrane
75
Why is membrane asymmetry important?
The properties of the two sides of the membrane differ
76
Explain the roles of compertmentalization in cellular function
• Membrane bound organelles advantage:
o Allows for specialisation
• Membrane bound organelles advantage:
o Allows for specialisation
• Due to their membrane, cells can:
o Receive information through cell signals
o Can regulate import and export of molecules
--Selectively permeable
o Are able to move and expand
Membrane fluidity
• Lipid molecules can move laterally within membranes
77
What are the main features of a molecule that affect the permeability of a membrane
• The main features of a molecule that affect its permeability are size, electrical charge and lipid solubility
o Molecules with high lipid solubility have high permeabilities
o Hydrophobic and hydrophilic molecules have difficulty in penetrating the membrane
o Electrically charged molecules have low lipid solubility and therefore have low membrane permeabilities whereas neutral gases have high membrane permeabilities
78
How do bacteria exchange genetic information?
• Bacteria exchange plasmids circles of nucleic acids
• Bacteria swaps plasmid
o More strong and able to survive in a selective environment
• Pili anchor down into substrate and bring bacteria close to facilitate exchange
• Slow down replication when we see that nutrients are depleted
79
How can ATP put energy into a reaction?
o Proteins folding
o Coupled reaction
Phosphorylate a molecule which can increase chance of it interacting with another kind of molecule
80
What is the protein pathway?
• Rough ER produces protein
• Protein goes into cis side of golgi body to the trans face, which modifies the protein and puts it in a vesicle
• Vesicle that carry secreted cargo travels along microtubule
• Vesicle fuses with plasma membrane through exocytosis
o Intracellular vesicles fuse to the plasma membrane and the contents of the vesicle are deposited on the outside of the cell
81
How do mitochondria undergo fusion and fission, and why would they do this?
• Mitochondria can form mitochondrial networks through fusion
o This occurs when the DNA is damaged in 1 mitochondria, so a healthy mitochondria fuses with the damaged mitochondria
o The damaged DNA breaks down and the healthy mitochondria shares its healthy DNA
o The fused mitochondria split apart again, with the two mitochondria now having healthy DNA
82
When did the mitochondria first fuse together?
o During the early stage of embryo (when there is no tail) –many mitochondria
o In later stage with tail, underwent fusion to form one big mitochondria
83
What is the function of the mitochondria?
```
o Provide energy in the form of ATP
Electron chain
o Steroid hormones
o Apoptosis
Programmed clean cell death
• Destroyed from inside
• Packed into vesicle
• Eaten by macrophage
Used to protect from cancer cells
Apoptosis can remove dangerous cells from body and sculpt tissue in development
```
84
What are mitochondria usually attached to in the cell?
Microtubules of the cytoskeleton and sometimes actin
85
How do mitochondria move along the microtubule?
o Adaptor motor (when they get phosphorylated they move) proteins link microtubules and vesicle/mitochondria and can move them across the microtubule
86
What are the 3 components of the cytoskeleton?
- Microfilaments
- Microtubules
- Intermediate filaments
87
What are microfilaments made of?
Actin
88
Where are microfilaments usually found?
Around the outside of the cell
89
What are microtubules made of?
Spiral of Tubulin and subunits
90
Where can microtubules be found?
Tend to radiate out from the nucleus towards the peripheral of the cell (except in mitosis)
91
What can microtubules do?
Can grow and shrink depending on their needs
| • Elongate the nose and shrink the tail of the cell to allow the cell to move
92
What are intermediate filaments made of?
Made of various proteins, often keratin wound into ropes with little elasticity
93
What are intermediate filaments useful for?
For reinforcement
| Makes sure cell doesn’t bulge out too much when squashed or move in a damaging configuration
94
What is the concentration gradient?
Movement of particles from high to low concentration
95
What is the electrical gradient?
the difference in charge between the fluid compartments on either side of a membrane
96
What is the electrochemical gradient
A combination of the electric gradient and concentration gradient
97
Describe the process of facilitated diffusion through channels
o Channels in membrane which open and close
o Just open up and allows the rapid flow along the concentration gradient
o The opening and closing of channels can be likened to the opening and closing of a gate that is controlled by various signals
98
What are 3 different types of protein channels?
Voltage-gated channels- open or close in response to changes in the voltage across the membrane
Ligand-gated channels- activated by the binding of specific molecules
Mechanically gated channels- response to physical disturbance
99
What is powered transport and how does it work?
o Channels powered by ATP
o Binding of a solute on one side of the membrane induces, through ATP phosphorylation, a conformational change, which exposes the solute on the other side of the membrane, where it is released
100
What is endocytosis and what is its process?
o Endocytosis-
Type of active transport that moves particles, such as large molecules, into a cell.
Folding inward of a cell’s plasma membrane to surround macromolecules or other matter diffusing through the extracellular fluid
The encircled foreign materials are then brought into the cell, and following a pinching-off of the membrane, are released to the cytoplasm in a sac-like vesicle
101
What is receptor mediated endocytosis and how does it work?
Through receptor mediated endocytosis, active cells are able to take in significant amounts of particular molecules that bind to receptor sites extending from the cytoplasmic membrane into the extracellular fluid surrounding the cell
The internal surface of the membrane adjacent to the receptor is coated with the protein clathrin, which anchors the receptor protein and causes the membrane to fold inwards to forma pit when activate by the binding of the solute to the receptor
• Used for bringing cholesterol into human cells
Once freed into the cytoplasm, several small vesicles produced via endocytosis may come together to form a single entity, the endosome
Endosome transports their contents to a lysosome, which subsequently digests the materials
OR endosomes can be used by the cell to transport various substances between different portions of the external cell membrane
102
What is phagocytosis?
Large particles are taken in by a cell
103
What is pinocytosis?
A process that takes in molecules which the cell needs from the extracellular fluid
Able to ingest drops of liquid
Results in a much smaller vesicle than does phagocytosis
104
Where is the epithelium tissue found?
• Epithelia are a diverse group of tissues that form continuous layers covering the body surface as well as cavities and tubes inside the body.
105
What is the purpose of the epithelium tissue?
• Epithelia, therefore, function as interfaces between adjacent biological compartments, and between the organism and its environment, where they provide protection and regulate the exchange of materials, and secretion
-Waterproof and absorbs nutrients
106
What are the structural properties of the epithelium
| DRAW and DESCRIBE
• Has microvilli at the top
o Actin is in the microvilli
• Epithelia is anchored to the basal lamina
o Made of connective tissue
• Epithelial cells are closely bound together by a variety of tight and anchoring junctions and are supported by a basal lamina in which diffusion occurs
• Cytoskeleton holds cell together
107
What transport is used through the apical membrane?
Active
108
What transport is used through the basal membrane?
Passive
109
What are different types of epithelial tissue?
- Simple squamous
- -Very thin layer across which diffusion can occur
- Cuboidal simple
- -Secretion and absorption
- Stratified squamous
- -Provides protection
- Stratified cuboidal
- Simple columnar
- -Protection and functions in secretion and absorption
- Stratified columnar
- Pseudostratified columnar
- -Movement and provides protection
110
What can the basal lamina do for cancers?
Hold back metastasis for a while
111
What is a begnin tumor?
-Outside of bloodstream such as warts
112
What is a malignant tumor?
-Inside bloodstream
113
What does the nervous tissue do?
* Allows the multicellular animal coordinated movement and behavior
* Neurons are specialized to carry information rapidly and precisely from sensory structures to effector structures
114
What is connective tissue made of?
- Cells
- Fibres
- Ground substance
- The matrix (ground substance+ fibres and non-living part of the tissue)
115
What are the three different types of fibres that make up the connective tissue?
* Collagen-principle type
* Reticulin-supporting connective tissue such as in kidney and liver
* Elastin- bladder and skin
116
What is the function of connective tissue?
• Connective tissues provide basic structural, metabolic and defensive support for other tissues of the body
117
What is the function of loose connective tissue?
Provides support, insulation, food storage and nourishment for epithelium
118
What is the function of dense connective tissue?
Provides flexible, strong connections
119
What is the function of bone connective tissue?
Protects internal organs: provides rigid support for muscle attachment
120
What is the function of cartilage connective tissue?
Provides flexible support, shock absorption and reduction of friction on load-bearing surfaces
121
What is the function of blood connective tissue?
Means of communication between organs
122
What does skeletal muscle tissue look like, and in what dimension does it work?
DRAW A DIAGRAM
Only work in 2D
Straight unbranched fibers
Stripes and striations
Multiple nuclei
-Myoblast join together and form myofibrils which retain all nuclei
Voluntary muscle
Move to stabilise the position of the skeleton
Guard entrances and exits of the digestive, respiratory and urinary tracts
Generate heat
Protect internal organs
123
What does cardiac muscle look like, and what dimension does it work in and what is its function?
DRAW A DIAGRAM
```
Only work in 2D
Branched fibres
Striations
Has intercalated disks
Moves blood and maintains blood pressure
```
124
What does smooth muscle look like, and what dimensions does it work in and what is its function?
DRAW A DIAGRAM
Only work in 3D
Spindles
Smooth muscle moves food, urine and reproductive tract secretions
Controls diameter of respiratory passageways and blood vessels
125
What can signals instruct cells to do?
o Survive
o Grow and divide
o Differentiate
o Die
126
What affects signal speed?
• When signals go to enzyme in cytoplasm, fast reaction time, but if it goes through nucleus, it is slower
127
How do steroid hormones signal?
Goes through membrane inside cell hydrophobic
| Pass through plasma membrane, combine with a cytoplasmic receptor and then pass into the nucleus to interact with DNA
128
How do neurotransmitters signal?
Open up a channel
Neurotransmitters cannot pass through the plasma membrane: they interact with a receptor on the surface and can induce a direct change in membrane channel properties
129
How do protein hormones signal?
Hydrophilic -->interacts with receptor on membrane
Peptide hormones also cannot pass through the plasma membrane and must bind to a surface receptor, but their action requires signal-transducing second messengers such as cAMP
130
How does the stress response work?
• Vasopressin uses the phospholipase C intracellular messenger system
• Vasopressin can also release ACTH
o This is a protein hormone so needs to interact with receptor on membrane
o Two proteins joining together can change shape and activate, so receptors changes shape and activates several proteins
o Activates a kinase which phosphorylates and activates other proteins needed
• Brain recognizes stress response, hypothalamus deals with signal and releases CRH (corticotropin releasing hormone), which stimulates the release of adrenocorticotrophic hormone (ACTH) by pituitary which goes into the blood and reaches the adrenal gland cortex
• Cortisol (a steroid) is released by the cortex of the adrenal gland and is hydrophobic, so can go straight through the plasma membrane
• For the first few seconds of stress, the medulla of the adrenal gland produces adrenaline straightaway
• The cortisol starts increase fat and protein breakdown and increasing blood glucose levels
131
How do viruses survive?
Depends on host cell for replication and metabolism
132
What is the argument for why viruses are alive?
nucleic acid surrounded by protein coat and can evolve
133
What is the argument for why viruses are not alive?
Dependent on host cell to survive
134
What is an example of a virus?
Influenza virus
135
How does a bacteria survive?
Has own metabolism and replication
136
What is the structure of the bacteria?
- Unicellular structure: smallest free-living organism
| - Prokaryote
137
What is an example of a bacteria?
Mycobacteria
138
How does a fungi get food?
-Secrete enzymes to digest material around them and absorb sugar: they are sessile
139
How big are fungi?
Multicelllular and macroscopic
140
Are fungi prokaryotes or eukaryotes?
Eukaryotes
141
What is an example of a fungi?
Mushroom
142
What is an example of protists?
Malaria
143
How do protists get food?
Move around to hunt their food and engulf it
144
How big are protists?
-Large complex cells
145
Are protists prokaryotes or eukaryotes?
Eukaryotes
146
How do algae get food?
Photosynthetic organisms
147
How big are algae
Large complex cells
148
Are algae prokaryotic or eukaryotic
Eukaryotes
