1
Q
Cell organelles
A
Cell membrane - determine what enters and leaves
Nuclear membrane - seperate DNA from cytoplasm
Golgi apparatus - vesicles involved in cellular transport
Centrioles - develop spindle fibres in mitosis
2
Q
Cell organelles
A
Lysosomes - contain degradative enzymes
Endoplasmic reticulum - ribosomes attach for protein Transport
Chromatin - materials chromosomes consist of
Micro tubes - give cell its shape
3
Q
Cell types
A
Eukaryotic - cell has nucleus and organelles
Prokaryotic - unicellular, no organelles
4
Q
Structure of cell membrane
A
Hydrophilic head Phospholipid bilayer Hydrophobic tail Carbohydrates chain Protein molecules Glycolipid Glycoprotein
5
Q
Diffusion
A
Passive transport
Random movement
High concentration > low concentration
Fat soluble sand small molecules
6
Q
Osmosis
A
Passive transport
Hypotonic - low solute, high water - Bursts
Hypertonic - high solute, low water - shrivels
Isotonic - equilibrium
7
Q
Facilitated diffusion
A
Passive transport
Channel proteins - water molecules
Carrier proteins - large molecules
Along concentration gradient
8
Q
Carrier mediated
A
Active transport
Protein pumps
Transport proteins that need energy
9
Q
Endocytosis
A
Membrane infolds around
Solid - phagocytosis
Liquid - pinocytosis
10
Q
Exocytosis
A
Membrane fuses with material
Change shape of cell
11
Q
Factors affecting transport
A
Surface area Volume Concentration gradient Amount of moisture Cell thickness
12
Q
Lock and key model
A
- enzyme is substrate specific
- enzyme substrate complex, join at active site when reaction occurs
- transition phase, bonds between substrate are broken (catabolic)
- enzyme releases products and catalyses another substrate
13
Q
Cellular respiration
A
Anaerobic - without oxygen
Glucose = lactic acid + carbon dioxide + ATP
Aerobic - with oxygen
Glucose + oxygen = carbon dioxide + water + ATP
14
Q
ATP
A
adenosine triphosphate
Each cell breakdown releases 38 ATP
ADP + Pi = ATP
Weak bond to easily revert
15
Q
Energy use by cell
A
- building complex molecules
- active transport
- cell division
16
Q
Nutrients
A
Water - reactions occur in water
Carbohydrates - main source of energy, glucose
Lipids - broken to fatty acids and glycerol
Proteins - broken into amino acids
Minerals - part of enzymes
17
Q
Digestive nutrients
A
Amino acids - help structure, function and regulate organs
digested by stomach and duodenum
egg, fish, milk, meat
Carbohydrates - provide energy
digested by stomach, mouth and pancreas
Oatmeal, brown rice, bread, pasta, potatoes
Glycerol and fats - storing energy as fat
digested by mouth, small intestine, pancreas, liver
Milk, cheese, meat, butter, oil
18
Q
Mouth
A
Mechanical and chemical
Teeth and tongue grind food
Tongue makes bolus
Salivary glands - sublingual, submandibular, parotid
19
Q
Oesophagus
A
Circular muscles
Longitudinal muscles
Mucus lining aids food down
Peristalsis - wave of muscle contraction
20
Q
Stomach
A
Goes through cardiac sphincter
- holding tank and mixing chamber
- control hunger hormones
- mechanical and chemical digestion
- hydrochloride acid to kill bacteria
Chyme from gastric juices
Mucosa neck cells
Parietal cells
Chief cells
21
Q
Small intestine
A
Duodenum
Jejunum
Ileum
- lining of mucosa
- highly folded and villi to increase surface area
Intestinal and pancreatic juices neutralise chyme
Gall bladder stores bile to emulsify food - surface area
22
Q
Large intestine
A
Thick and short No villi or digestive juices Slow movement 18 - 24 hours - absorption of electrolytes - bowel contents solidify - bacteria ferment food - 500ml of gas per day
23
Q
Digestion
A
Mechanical - physically breaking down food into smaller pieces
Chemical - breaking down food into simpler molecules to be used by the cells
24
Q
Digestive enzymes
A
Mouth - salivary amylase, lingual lipase, lysosomes
Stomach - gastric protease, gastric lipase
Pancreas - pancreatic amylase, pancreatic protease, pancreatic lipase, ribonuclease, deoxyribonuclease
25
Enzyme function
Amylase - carbs into disaccharides sugars
Protease - proteins into amino acids
Lipase - lipids to fatty acids and glycerol
26
Villi
Finger like
Move like coral
Blood absorption - sugar, amino acids, water
Lacteal absorption - fatty acids, glycerol
27
Deamination
Amino acid + oxygen = carbohydrate + ammonia
| Ammonia + energy + carbon dioxide = urea + water
28
Urine
95% water
2% urea
3% Uris acid and sulphate
29
Urine filtration
- renal corpuscle - glomerulus and glomerular capsule
- afferent arteriole wider than efferent arteriole causing high blood pressure to force through water and dissolved blood not permeable cells
- resultant fluid is filtrate
- all materials in blood except cells and proteins are filtered
30
Urine reabsorption
- renal tubule lining - proximal convoluted tubule and descending tubule
- water, glucose, amino acids and chloride are absorbed
- large surface area achieved by length of tubule and microvilli
- materials from filtrate are reabsorbed into blood
31
Urine secretion
- distal convoluted tubule and ascending tubule
- Any unrequited materials that were absorbed are put back into filtrate
- when filtrate reaches collection duct it is urine
- drugs, hormones, excess water are secreted
32
Excretory organs
```
Kidneys - urine
Intestine - faeces
Liver - toxins
Skin - sweat
Lungs - CO2
```
33
Hypothesis
If...then statement
Short and definite
Contain both variables
Suggested explanation for observations that give rise to a problem
34
Variables
Independent - changed or tested
Dependant - measured, change in response to independent
Controlled - remain constant
35
Tests
Control - doesn’t receive variable, give base line data to compare with
Experimental - receive tested variable
36
Data
Qualitative - descriptive data
Quantitative - numerical data
Placebo - inactive substance, looks like real thing
37
Ethics
```
Honesty and integrity
Carefulness
Confidentiality
Legality
Objectivity
```
38
Microscopy
Total magnification
Mag of ocular x mag of objective
Field of view
Low mag - mini grid
High mag - low f.o.v x mag at low/mag at high
Size of object
f.o.v/ times can fit
Scale of drawing
Size of drawing/ size of object
39
Reactions
Anabolic
- building metabolic process
- requires energy
- simple molecule to complex
Catabolic
- destructive metabolic process
- release energy
- complex substance to simple molecule
40
Epithelial tissue
Covering or living
Outer layer of skin, Heart, intestines
Cells closely joined
Thin and flat or column/cubes
41
Connective tissue
Support and hold body together
Cells separated by cell matrix
Bone, cartilage, tendons, ligaments
42
Nervous tissue
Specialised cells called neurons
Long projections from body of cell
Projections carry signals
Brain, spinal cord, nerves
43
Muscular tissue
Skeletal - striated, bones, voluntary control
Involuntary - smooth, non-striated, wall of stomach, intestines
Cardiac - involuntary, heart
44
Enzymes
```
Protein that catalyses reactions
Reaction specific
Lowers activation energy in reactions
Not used up in reaction
Denatured by heating
```
45
Function of skeleton
```
Protection of organs
Movement
Blood production
Support
Mineral storage
```
46
Composition of bone
Periosteum - fibrous connective tissue surrounding bone
Compact bone - dense bone making up bulk of skeleton
Spongy bone - porous bone found in the end of long ones and middle of short bones
Bone marrow - found in cavities of bones
47
Osteocytes
Osteoblasts - bone formation in periosteum and endosteum
Osteocytes - maintain mineral concentration of matrix in matrix
Osteoclasts - bone reabsorption at old or injured bone sites
48
Parts of a long bone
Articulatory cartilage - reduce friction and absorbs shock of movable joints
Endosteum - membrane lining cavity of bone
Periosteum - tough fibrous membrane surrounding parts without cartilage
Medullary cavity - fatty yellow bone marrow
49
Muscular system roles
Facilitate movement
Generate heat
Support posture
Give shape to body
50
Muscular system features
Contractability
Extensibilty
Elasticity
51
Antagonistic muscle pairs
Muscles cannot push bones away by themselves
Work in pairs
Co ordinate in opposite directions
Agonist - bicep
Antagonist - tricep
52
Sliding Filament Theory
Cross bridge formation
- myosin binding sites must be exposed
- nerve impulse stimulates release of calcium
- calcium combines with troponin on tropomysin
- causes tropomysin to move and expose binding site
53
Sliding filament theory
The power stroke
- myosin heads pivot
- move actin filament closer to M line
- multiple heads perform power stroke
- sacromere shortens as z line moves closer together
54
Sliding filament Theory
Cross bridge detached
- ATP attaches to myosin heads
- weakens bond between myosin & binding site on actin
- cross bridge is detached
55
Sliding filament Theory
Reactivation of myosin head
- energy is used to return myosin head
- cycle repeats while calcium present and site exposed
- cycle stops when calcium is back in sacroplasmic reticulum
- tropomysin shifts and troponin covers the binding site
- muscles relax
56
Structural joints
Fibrous - no movement, fibrous tissue, teeth, jaw
Cartilage - slightly movable, held by cartilage, ribs, sternum
Synovial - synovial fluid, limited movement, knee, elbow
57
Functional joints
Immovable
Slightly movable
Freely movable
58
Secretion
Endocrine
- directly into blood or tissues
Exocrine
- through ducts to outside of body
59
Faeces contents
Water
Undigested food
Bile pigments
Broken blood cells
60
Transcription
Initiation - chemical messenger binds to DNA at gene, signals to RNA polymerase to bind with DNA, RNA polymerase reaches start codon
Elongation - double helix relaxes and hydrogen bonds broken, complementary free nucleotides make mRNA strand
Termination - RNA polymerase reaches stop sequence and mRNA is released to ribosome
61
Translation
Initiation - mRNA enters ribosome and binds at ‘codon binding site’, moves through ribosome until start codon e.g AUG
Elongation - tRNA retrieves specific amino acid from cytoplasm which contains anti-codon to match codon, tRNA deposits the amino acids at the ribosome, ribosome creates peptide bond between acids
Termination - stop codon is read and mRNA is released to golgi to be packaged into functional protein
62
Methylation
Methyl groups CH3 is added or removed between guanine and cytosine
Addition - gene silenced and RNA polymerase blocked because can’t fit
Removed - gene activated because RNA polymerase can fit on
Folate
Choline
Methionine
Vitamin B
63
Histone Modification / Acetylation
DNA is negative charged and Histone is positive charge
They attract together - less space between them for RNA polymerase and gene is silenced
Acetyl groups are negatively charged
Attached to histones to repel DNA, more space for RNA polymerase and gene is activated
64
Respiratory Organs
Nasal cavity
- projections increase surface area
- filter, warm and moisten air
- resonating chamber for speech sounds
- hair and mucous trap dust
Larynx
- organ of voice
- air passes to lungs
- vocal cords vibrate for sounds
65
Respiratory organs
Trachea
- carries air to lungs
- lined with mucous and cilia - beat to move dust upwards
Bronchioles
- fine tubes with smooth muscle walls
- end in alveoli
Alveoli
- air sacs that make up most of lungs
- very thin walls for gas exchange
66
Respiratory Organs
Intercostal muscles
- muscles between ribs
- move rib cage up to increase volume when inspiring
Diaphragm
- muscle separates chest from abdomen
- flatten whilst breathing in to increase volume
67
Inheritance
X-linked
Female XX
Male XY
Autosomal
Rr RR rr
68
Genetic Diseases
Huntington’s disease - autosomal dominant
PKU - autosomal recessive
Haemophilia - x-linked recessive
69
DNA Structure
```
DNA
Double stranded helix
Hydrogen bonds
Backbone - phosphate, deoxyribose sugar
Nitrogenous bases - adenine, guanine, thymine, cytosine
Nucleotide - base, sugar, phosphate
```
70
Inspiration of breathing
Diaphragm contracts and flattens
Intercostal muscles contracts to mow ribs up and out
Pressure inside lungs decreases and vacuum created
Air sucked in until pressure equalises
Increases cavity volume
71
Expiration of breathing
Diaphragm relaxes and returns to dome shape
Intercostal muscles relax - abdomen move in and down
Pressure inside lungs increases and vacuum outside
Decrease cavity volume
72
Female Reproduction
Vagina - form birth canal, receive penis
Uterus - protect and nourish foetus
Fallopian tube - carry ova from ovary to uterus
Ovary - production of ova, release of oestrogen and progesterone
Cervix - produce mucous
Fimbriae - direct egg into Fallopian tube
Labia - barrier for protection
73
Male Reproduction
Scrotum - single pouch 2 testes, contract for warmth
Testes - seminiferous tubules produce sperm and testosterone
Vas deferens - carry sperm from epididymis to urethra, extends up from testes
Epididymis - stores sperm until matured
Prostate gland - thin milky alkaline fluid
Seminal vehicle - thick sugary fluid
Cowper’s gland - clear mucous
74
Hormones
FSH - targets ovaries and seminiferous tubules to mature and produce ova and sperm
LH - targets ovaries and interstitial cells of testes to secrete oestrogen and progesterone and testosterone
OEST - targets ovarian follicle to develop reproductive organs
TEST - targets testes to develop reproductive organs and sperm
PROG - targets breaths and Placenta to develop milk glands and Placenta
75
oogenesis - before birth
- millions of oogonia develop via meiosis
- mitosis stops before birth : finite amount
- all oogonia develop into primary oocytes and begin meiosis 1 : pause at prophase 1
- follicle cells nourish and protect primary oocyte
- 400,000 remain after birth
76
oogenesis - at puberty
- 1 primary oocyte develops monthly
- FSH released and targets follicle to release oestrogen
- oestrogen acts on primary oocyte to complete meiosis 1
- secondary oocyte starts meiosis 11 : pauses at metaphase 2
- ~14 days
77
oogenesis - after ovulation
- egg released into fallopian
- if no fertilisation - remains dormant and expelled in menstrual cycle
- if fertilised - quickly finishes meiosis 2 and produces a mature ovum
78
fertilisation 1
- sperm reaches ovum and forces head against corona radiata
- acrosome breaks releasing enzymes
- enzymes break down the corona radiata
79
fertilisation 2
- sperm head penetrates corona radiata
- fertilisation barrier forms around corona radiata and severs head from tail
- no other sperm can enter and secondary oocyte quickly completes meiosis 2
80
fertilisation 3
- pronuclei fuze to form a diploid zygote
- totipotent stem cells become anything
- zygote starts to divide ~1 day later
81
labour
pre-labour - head pushes on uterus, oxytocin is released causing the uterus to contract, cervix dilates to 4cm
dilation - cervix dilates from 4-10cm, forms birth canal
expulsion - head faces spine to fit through, contractions increase to force body, head exits birth canal, shoulders turn to fit through, foetus expelled ~30 minutes
expulsion of placenta - 5-10 minutes after expulsion, uterus is still contracting
82
germ layers
*process called gastruation
inner - endoderm - epithelial tissue of intestines, liver and pancreas
middle - mesoderm - skeletal muscle, smooth muscle, heart, blood and kidneys
outer - ectoderm - nervous system, hair, pigments cells
83
amniotic sac and placenta
amnion - cells surrounding embryo, forms the sack and amniotic fluid is secreted - acts as a shock absorber and temperature regulator
chorion - villi project into endometrial lining and form main part of placenta
amniotic sac and chorion fuse together
chorion continues developing and placenta is fully formed by 12 weeks to produce progesterone
84
twins
maternal - one egg splits after fertilisation, has same genetic material
fraternal - two eggs fertilised separately, genetically unique
85
contraception
sterilisation - tubal ligation, vasectomy
chemical - spermicide, pill, implanon, depo perova, nuva ring
physical barriers - condom, diaphragm, cervical cap
86
assisted reproduction
```
IVF - sperm in dish
GIFT - mix immediately
ICSI - single sperm
AID - semen donated
surrogacy - woman bears child
donor - different egg
```
87
mitosis
I - DNA duplicates to prepare for cell division
P - chromatin becomes chromosomes, spindle fibres grow from centrioles, centrioles migrate to opposite poles, nuclear membrane disappears
M - chromosomes lie along midline, spindle fibres attach to centromeres
A - centromeres divide into 2 and spindle fibres pull chromosomes to opposite poles, each pole has identical set of genes
T - chromatin uncoils and new nuclear membrane appears, spindles disappear
C - cytoplasm divides into two, each with own nucleus
88
differentiation
totipotent stem cells - any cells necessary for embryo development
pluripotent stem cells - many but not all cells - foetal tissue but not placental tissue
multipotent stem cells - can become cells with particular function - blood cells become erythrocytes, leukocytes and thrombocytes
89
meiosis 1
I - chromosomes replicate in preparation for meiosis, become chromatin
P - chromosomes condense and nuclear membrane breaks down, crossing over occurs
M - pairs of homologous chromosomes move to the equator, attach to spindle fibres
A - homologous chromosomes seperate to opposite ends to cell
T - cytoplasm divides and two cells are formed, each cell has duplicated chromosome from each pair
C - divides into two haploid cells
90
meiosis 2
P - new spindle forms around chromosomes
M - chromosomes line up at equator, each centromere attaches to 2 spindle fibres
A - centromeres divide, chromatids move to opposite poles of cells, now individual chromosomes
T - spindle fibres disappear, nuclear membrane forms around each set of chromosomes
C - divide into four new cells - 3 polar body and one mature ovum
91
crossing over
prophase 1 of meiosis
when pairing up, chromosomes can tangle
causes them to break and reattach wrongly
causes new combination
alleles further apart are more likely to break
*chromosome 23 on males does not cross over
92
non-disjunction
chromatids fail to seperate during meiosis 2
one of daughter cells has extra/less chromosomes
trisomy - down syndrome
monosomy - miscarriage
93
mutations
gremlin - transmitted to offspring
somatic - not on gametes, not transmitted to offspring
chromosomal - several genes are mutated
gene - specific genes nucleotide sequence is altered
94
blood components
erythrocytes - red blood, 40% of blood, live 120 days, take oxygen from lungs to body
leukocytes - white blood, 1%, varying lifespan dependant on disease etc., protect against disease, remove dead cells
thrombocytes - blood clotting, 4%, small platelets, no nucleus
plasma - mainly water - 55%
95
blood clotting
- tear in vessel, chemical message sent, thrombocytes stick and cover damage, form 'platelet plug'
- coagulation factors add to plug, produce fibrin net, hold plug together
- red/white blood attached for strength, clot contracts, edges of vessel come together, after repair the clot is broken down and removed
96
cardiac output
amount of blood pumped around body in a minute
97
stroke volume
amount of blood pumped with each beat
98
heart rate
speed at which the hearts beats
99
oxygen transport
3% in plasma
97% combined with haemoglobin > oxyhaemoglobin
Hb + O2 = HbO2
oxyhemoglobin - bright red
deoxyhaemoglobin - dark purple
100
carbon dioxide transport
```
8% in plasma
22% combines with haemoglobin > carbaminohaemoglobin
70% bicarbonate ions in plasma
CO2 + H2O = H2CO3 = H + HCO3
can reverse in alveoli
```
101
circulation
pulmonary - deoxygenated blood from heart to lungs
systemic - oxygenated blood from heart to body
102
arteries
```
away from heart
pulse present
high blood pressure
oxygenated blood
thick walled
```
interna - epithelial
media - smooth - thickest
externa - connective
103
veins
```
towards heart
no pulse
low blood pressure
deoxygenated blood
thin walled
```
interna - epithelial - thickest
media - smooth
externa - connective
104
capillaries
thin walled
one cell thick
no pulse
gas / nutrient exchange
105
blood flow
vasoconstriction - reduce of blood flow to organs, muscles contract
vasodilation - increase blood flow to organs, muscles relax
106
cardiac cycle
atrial systole - 0.1 seconds, SA node sends nerve impulse down both atria, atria contract forcing blood into ventricles
ventricular systole - 0.3 seconds, nerve impulse aches AV node, perking fibres cause ventricles to contract, tri/bicuspid valves close, forcing blood into pulmonary artery and aorta
diastole - 0.4 seconds, both atria and ventricles relax and fill with blood
107
lymphatic system
- collects fluid that escapes blood capillaries and returns it to the circulatory system.
- internal defence against disease causing organisms
- network of tissues and organs
108
lymph nodes
```
glands
bean shaped
neck, armpits, groin
1mm-25mm
surrounded by connective tissue
```
109
newborn circulation umbilical arteries
foetal - material exchange at placenta between foetal blood and maternal blood
newborn - cutting the umbilical cord causes vesicles to constrict to prevent blood loss and increase of blood pressure in circulatory system
110
newborn circulation ductus venosus
foetal - acs as a liver bypass, foetal wastes are removed at the placenta and cleansed by paternal liver.
newborn - cutting of umbilical cord causes increased blood pressure to vessels entering liver so blood flows in and ductus venosus disappears
111
newborn circulation ductus arteriosus
foetal - acts as a lung bypass, blood travels from pulmonary artery to aorta, high pressure in lungs from amniotic fluid, speeds up circulation of oxygenated blood
newborn - breathing reflect from CO2 build up, lungs become functional reducing pressure, blood flow becomes easier, blood flows through pulmonary artery to lungs, fades away because not used
112
newborn circulation foreman ovale
foetal - acts as a lung bypass, blood travels from right to left atria, speeds up circulation of oxygenated blood
newborn - increase pressure in heart causes hole to close over, blood forced into heart normally, reaches lungs for oxygenation
113
DNA location and function
nuclear - nucleus
mitochondrial - mitochondria
DNA - stores information for proteins to determine contents of cells
mRNA - translated into proteins
tRNA - deliver amino acids to ribosome
rRNA - link amino acids to form proteins
114
DNA replication
step 1 - double strand relaxed by gyrate and bonds are broken by helicase
step 2 - nucleotides match with exposed base pairs, DNA polymerase joins the bases by catalysing the bonds and proof reads for any misplaced nucleotides
step 3 - enzymes move along relaxing the DNA strand to expose bases
115
genes
structural - nucleotide sequence provides code for protein
promoter - promote transcription by acting as biding site for DNA and RNA polymerase
regulator - codes repressor proteins to block DNA polymerase
RF off + PG on + SG on = Transcription
116
menstrual cycle
follicular phase - 1-14 days, FSH rises
ovulation - day 15, LH, FSH, PROG all rise
luteal phase - 15-28 days, PROG rises to rebound endometrial lining
menses - drop in all hormones
Human Bio 11
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