LEARN Flashcards
(87 cards)
1
Q
Ribosomes
A
where PROTEIN SYNTHESIS occurs
2
Q
Cell membrane
A
controls passages of SUBSTANCES IN AND OUT of a cell
3
Q
Mitochondria
A
where most ENERGY is RELEASED during respiration
4
Q
Cytoplasm
A
most of CHEMICAL REACTIONS take place here
•proteins are assembled in the cytoplasms of a cell
5
Q
Nucleus
A
CONTROLS THE ACTIVITIES of the cell- containing instructions for making new cells
•contains the CHROMOSOMES that carry the genes
6
Q
Chloroplast
A
ABSORB LIGHT ENERGY to make food via PHOTOSYNTHESIS
7
Q
Vacuole
A
(hole) filled with CELL SAP
8
Q
Flagellum
only in some bacterial cells
A
a whip-structure that allows a cell to move
9
Q
Plasmids
only in some bacterial cells
A
extra-chromosomal DNA
10
Q
📷Slime capsule
only in some bacterial cells
A
a easily removable, unorganised layer of extra cellular material that surrounds bacteria cells
11
Q
Eukaryotic
A
- DISTINCT MEMBRANE-BOUND NUCLEUS CONTAINING DNA (animal, plant, fungus)
- LARGER than prokaryotes
- LARGER RIBOSOMES
- contain MEMBRANE BOUND ORGANELLES
12
Q
Prokaryotic
A
•(no distinct membrane-bound nucleus) DNA free floating in the CYTOPLASM
Often found in the form of a ‘plasmid’, a CIRCULAR PIECE OF DNA
•SMALLER than eukaryotes
•SMALLER RIBOSOMES
•NO MEMBRANE BOUND ORGANELLES
13
Q
Proteinsynthesis
A
- the BUILD UP of LARGE PROTEINS from mallet molecules
* occurs on RIBOSOMES
14
Q
Cell metabolism
A
the RATE at which CHEMICAL REACTIONS OCCUR in cells
15
Q
Enzymes
A
tiny PROTEIN MOLECULES that SPEED UP chemical reactions WITHOUT BEING USED UP in the process
16
Q
Magnification
A
HOW MUCH LARGER something looks than it’s actual size
• = size of image
————————
actual
- light microscope: x2000
- electron microscope: x2000000
17
Q
Resolution
A
the ability to DISTINGUISH BETWEEN 2 SEPARATE POINTS (sharper image)
- light microscope: 200nm
- electron microscope: 0.2nm
18
Q
Sperm
A
•fertilise egg •-long, streamlined tail —>swims to egg faster -lots of mitochondria —>releases energy for swimming -contains enzymes —>to digest the egg -contains half the number of chromosomes —>full chromosome number restored on fertilisation (with egg)
19
Q
Nerve
A
•translates electrical impulses and sends messages around the body
•-long and thin
—>able to transport impulses long distances
-has arch surrounded by a myelin
—>the sheath insulates the axon and speeds up impulses
-many dendries
—> allow each cell to make many connections to other neurones
20
Q
Palisade
A
•carry out photosynthesis •-packed full of photosynthesis —>can trap large amounts of light •long and thin —>can catch most light that passes through the leaves
21
Q
Root (hair)
A
•absorb water and mineral ions from soil
•-have a root hair
—>maximised surface area and increased amount of absorption
-contain lots of mitochondria
—>release energy for active transport of mineral ions
22
Q
Xylem
A
•transports water and minerals up the stem in a plant •-dead cells with no end walls —>form a hollow tube -cells are lined with lignin —>lignin make cells waterproof
23
Q
Muscle
- Cardiac (found in the heart)
- Striated (attached to skeleton)
- Smooth (makes up organs)
A
•idk
•-made of fibres
—>can contract to shorten and bring about movement
-contain lots of mitochondria
—>contraction requires energy in the form of ATP
-contain myoglobin, stores oxygen??
—>increases aerobic capacity
24
Q
Ciliated (epithiel)
A
•line trachea and Fallopian tubes. Associated With the goblet cells which produce mucus that trap substances
•-contain tiny hairs called cilia on the surface
—>cilia waft in a wavelike motion to move substances through the tube
25
Fat (adipose)
•-surround organs to provide protection + insulation
-energy reserve (store fat)
•-very little normal cytoplasm
—>extra more room to store fat
-very few mitochondria as they use little energy
-expandable membrane can grow to 1000 times its size
—>store more fat for more energy
26
Phloem
•transport dissolved sugars around plant
•-have sieve plates instead of solid end wall
-no organelles *always associated with companion cells
—>provide extra room for transport
27
Red blood
```
•transport oxygen around body
•-bioconcave shape
—>increases surface area
-full of protein haemoglobin
—>binds with oxygen to transport it
-no nucleus
—>can carry more haemoglobin
```
28
Egg (ovum)
•female sex cell (gamete)
•-very large cytoplasm
—>provides food for developing embryo once fertilised
-contains half the number of chromosones
—>chromosones carry genetic information from the mother to be passed on to the offspring
29
Cone
•found lining the retina in the eye and allow you to see in colour
•-contains a molecule called visual pigment
—>visual pigment undergoes chemical change in coloured light to detect colour
-lots of mitochondria
—>provide energy to reform the visual pigment
-have dendries
—> to form a synapse (connection) to the optic nerve that sends messages to the brain about colour images
30
White blood
•form body’s defence system against invading microorganisms
•-have phagocytes
—>engulf and digest foreign material
-contains special enzymes
—>to break down the foreign substances
-lymphocytes make antibodies
—>lymphocytes are protein molecules so they are full of protein
31
Microorganisms (4)
* bacteria
* fungi
* fungi
* proticista
32
Cell division (4 stages)
1) cell elongates and DNA is replicated
2) cell wall and plasma membrane begin to divide
3) cross-wall forms completely around divided DNA
4) cells separate
33
Lag phase
* pic
| * bacteria growing & making new enzymes
34
Log, or exponential growth, phase
Optimum growth condition, rapid cell divisions
35
Stationary phase
Birth rate = death rate
36
Death, or logarithmic decline, phase
Oxygen runs out, food runs out, toxic waste builds up
37
Chromosome
* a single molecule of DNA (deoxyribonucleic acid)
* we have 46 (23 pairs-one of each pair is from our mother and the other from our father) in each body cell
* our gametes (sex cells) only have a single set of 23 chromosones
38
Gene
•a small section of DNA on a chromosone
•each gene codes for a particular sequence of amino acids
——> join to make a specific protein
~1 gene codes for 1 protein
~3 bases code for one amino acid
39
Phenotype
•the physical way genetic information is expressed (the way you look)
40
DNA
a long molecule made up of 2 strands which are twisted together to make a double helix
41
Karyotype
all of the chromosomes of an organism lined up together
42
Allele
different forms of a gene
43
Nucleus
where the genetic information is found
44
Recessive
the characteristic that will show up in the offspring only if both of the alleles are inherited
45
Homologous
describes a matching pair of chromosomes
46
Gamete
a sex cell which contains half the DNA of the parent organism
47
Dominant
the characteristic that will show up in the offspring even if it is only one of the alleles inherited
48
🍏Homozygous
an organism where both given alleles for the traits are the same
49
Diploid number
the number of chromosomes every cell (except the sex cell) has
50
Haploid
the number of chromosomes the sex cell has (half of the diploid)
51
Mitosis
New cells are produced by old cells dividing
```
Pic
•mitosis takes place for:
-cell renewal
-growth
-tissue repair
-asexual reproduction
```
52
Interphase
* ‘resting’ phase
* cell grows
* increase in the number of organelles so that they can be split equally between the two daughter cells
* the DNA replicates to form two copies of each chromosome
53
Mitosis {Phrophase
Metaphase
Anaphase
Telophase}
nuclear division that allows production of two identical daughter cells
54
Cytokinesis
division of the whole cell
| •when you would expect 2 cells to first appear
55
Meosis
•nuclear division that produces gametes (animal- egg and sperm, plants- pollen) which have half the normal number of chromosomes
56
The forming of two genetically identical daughter cells
Pic DNA is found as chromosomes in the nucleus
Pic chromosomes become visible as each chromosome is copied and joined together
Pic chromosomes are pulled apart to opposite poles by contracting fibres
Pic the nuclear membrane disappears and the chromosomes line up along the centre of the cell
Pic the nuclear membrane forms around each group of chromosomes and the cytoplasm divides
Pic two genetically identical daughter cells are formed
57
🍏Cancer
large variably shaped nuclei —————>
many dividing cells; disorganised arrangement ———>
variation in size and shape ———>
loss of normal features
58
Stem cells
a stem cell is an UNDIFFERENTIATED cell that CAN REPLICATE ITSELF to form cells of the SAME TYPE or DIFFERENTIATE to form OTHER CELL TYPES
```
found:
•in plants:
-in the meristems
•in animals:
-embryonic stem cells
-some in umbilical cord of newborn babies
-some in adults
```
59
Differentiation
a cell differentiates to become SPECIALISED- CHANGING ITS SHAPE or the NUMBER or TYPE of SUB-CELLULAR STRUCTURES
60
Meristem cells
can be used to produce CLONES OF PLANTS QUICKLY and CHEAPLY
•cloning rare species to protect them
•growing crops with useful characteristics
61
Problems with stem cells
- process is slow, difficult and expensive
- fears that stem cells get out of control and cause cancer
- removing it from embryo causes it to die
- viral infections could be transferred
- adult stem cells only seem to grow in a limited number of cell types
62
Pros of Embryonic Stem Cells
- limitless self-renewal to generate lots of cells
- ability to differentiate into all cell types to treat many diseases
- cellular medicines can be made; cheaper than patient-specific treatments
63
Cons of Embryonic Stem Cells
- requires the destruction of an embryo
- patients require immunosuppressive drugs so that they don’t reject the cells
- many safety checks have to be carried out to make sure that these treatments are safe for the patient
64
Pros of Adult Stem Cells
- no ethical concerns
| - no issues of immune rejection since they are derived from the patient’s own cells
65
Cons of Adult Stem Cells
- limited self-renewal of the cells which restricts the size of the cellular therapy that can be generated
- limited number of cell types can be generated
- the generation of cellular therapies that are specific for each patient will be expensive
66
Equilibrium
when the CONCENTRATIONS are EQUAL THROUGHOUT AN AREA or INSIDE AND OUTSIDE A CELL
67
Diffusion
```
the movement of particles from an area of HIGH CONCENTRATION to an area of LOW CONCENTRATION (down a concentration gradient) until they reach EQUILIBRIUM
💫it is a PASSIVE PROCESS.
•Rate of diffusion determined by:
-🍎concentration gradient
-🍎temperature
-🍎surface area
-🍎distance
```
68
Net
overall (some particles might move in different directions but OVERALL MOVEMENT)
69
🍎Concentration gradient
| ~effect on the rate of diffusion
the bigger the difference in concentration either side of the membrane the faster the rate of diffusion
•cells can move substances to build up a concentration agency
70
🍎Temperature
| ~effect on the rate of diffusion
the higher the temperature the more kinetic energy the molecules have so the faster they move and the faster the rate of diffusion
•body temp~37°C
71
🍎Surface area
| ~effect on the rate of diffusion
the greater the surface area the more molecules can cross the membrane at the same time
•your cells are arranged with a large surface area to volume ration eg. lungs
72
🍎Distance
| ~effect on the rate of diffusion
the shorter the exchange surface the faster the rate of diffusion
•your cells have a very thin membrane
73
Osmosis
```
the net movement of WATER from an area of HIGH WATER CONCENTRATION to LOW WATER CONCENTRATION 💫across a partially permeable membrane
•Rate of osmosis determined by:
-🍎concentration gradient
-🍎surface area
-🍎distance
```
74
Hypertonic solution
HIGHER LEVELS OF SOLUTES than inside the cell
75
Hypotonic solution
LOWER LEVELS OF SOLUTES than inside the cell
76
Isotonic solution
has the SAME LEVEL OF SOLUTES as inside the cell
77
Furgid
| Animal cells
cell swells and bursts as there is no cell wall to resist the pressure
78
Flaccid
| Animal cells
water has left the cell and the cell shrivels
79
Lysed
| Plant cells
cell swells, cell membrane pushes against cell wall and cell wall pushed back
80
Cremated
| Plant cells
water has left the cell
81
Plasmolysed
| Plant cells
water has left the cell and the cell membrane has shrunk away from the cell wall
82
Potato cell Osmosis Investigation
- potato cell naturally contains a certain concentration of water particles
- the cell membrane is permeable to water particles, which pass into and out of the cell
- cell also contains a vacuole which contains a fairly concentrated solution of sugars and mineral ions
- the vacuole is also capable of storing water particles
83
🍎Osmosis
| ~potato cell investigation
if the concentration of water particles outside the the potato cell is
HIGHER than the cell, water particles will move INTO the potato cells of the cylinder
LOWER than the cells, water particles will move OUT OF the potato cells of the cylinder
EQUAL to the concentration inside the cell, water particles will move INTO and OUT OF the potato cells of the cylinder in EQUAL AMOUNTS
84
Percentage change
• = final - original
—————— x100
original
85
Active transport
the movement of particles of a substance AGAINST A CONCENTRATION GRADIENT (from low to high) USING ENERGY FROM RESPIRATION
💫•Requirements:
—>carrier proteins, which pump these particles across the membrane
—>energy in the form of ATP, molecule produced by respiration in mitochondria
💫•Required for:
-uptake of mineral ions from soil (doesn’t have many and the plant need some)
-movement of glucose from gut and kidney tubules into blood
-removal of salt from the body of marine animals
-absorption of ions from very dilute solutions
86
🍏Cyanide poisoning
cyanide (found in apple seeds) stops respiration in the mitochondria —>this means there is no energy for active transport
106
Respiration
* takes place in the mitochondria •the chemical reactions controlled by enzymes
* cellular respiration takes place continuously in ALL plants and animals
* glucose + oxygen ——> carbon dioxide + water + energy
•organisms respire:
>to build up a larger molecules using smaller ones
>cell division, growth and repair
>in animals to enable muscles to contract >in mammals and birds to maintain a steady body temperature in colder surroundings
>in plants to build up sugars, nitrates and other nutrients into amino acid’s which are then proteins
