biology end of year

what is a cell

a cell is the basic unit of life - all living things are made of cells

what does the nucleus contain and control

the nucleus contains DNA and controls what goes on in the cell

organells in the animal cell

cytoplasm, cell membrane, nucleus, ribosome and chloroplast

organelles in plant cell

cell membrane, nucleus, vacuole, cell wall, chloroplasts and ribosomes

what does mitochondria do

release energy in respiration

what do ribosomes do

proteins are made (synthesised) here

what does cell wall do

supports the cell and keeps it shape

what does vacuole do

full of cell sap and maintains shape

what does cell membrane do

controls movement of substances in and out

what does cytoplasm do

this is where many reactions take place

what does chloroplast do

light energy is absorbed and made into food

whydont animal cells need cell walls

as they rely on skeletons for support

what is a specialised cell?

a specialised cell is a cell with a specific shape, size or number of organelles to help it carry out its specific function

characteristics of a sperm cell

a streamlined head to swim faster, nucleus ‘haploid’(23 chromosomes) for fusing with the egg, flagellum/tail to help swim to eggs - good at chemical signals(sensing),

what do sperm cells contain

digestive enzymes to break down the egg membrane

characteristics of a egg cell

nucleus “haploid” for fusing with sperm, cell membrane hardens after one sperm cell enters (so zygote only has 46 chromosomes), jelly coat hardens after one sperm cell enters, large cytoplasm full of nutrients to develop into an embryo

what are cilated cells

dilated cells are cells which we find lining the inside of our windpipe and smaller airways. They also line the inside of a fallopian tube in a female to move the eggs along the uterus.

why are dilated cells specialised

highly specialised for their role in wafting bacteria and other particles(trapped by mucus) up the throat (to be coughed out) or down to the stomach (to be digested)

characteristics of a dilated cell(cilia)

cell membrane, nucleus, cytoplasm, mitochondria, hair-like projections from the cell

adaptions of cilated cells

extensions of the cytoplasm at the surface of the cell form hair-like structures called cilia which beat to move mucus and trapped particles up the throat

what is your metabolism

chemical reactions happening all together

what is a catalyst

a substance that speeds up the rate of a chemical reaction but is not itself changed by the reaction

what are enzymes

enzymes are biological catalysts that speed up reactions in living things

process of digestion 1

mouth - chewing

process of digestion 2

salivary glands - saliva contains amylase

process of digestion 3

asophogus, series of muscle contractions that move the food down your throat

process of digestion 4

stomach (churning, acid, some protease enzymes added)

process of digestion 5

liver(bile) - digestive juice that helps break down fat

process of digestion 6

gall bladder (holds bile)

process of digestion 7

pancreas (makes all types of digestive enzyme)

process of digestion 8

small intestine (digestive finishes and nutrients absorbed)

process of digestion 9

large intestine (water reabsorption)

process of digestion 10

an—(waste is expelled)

role of carbohydrate enzyme (add example)

EG AMYLASE, breaks down carbohydrates (eg starch) into glucose, enzyme made in the pancreas and salivary glands but works in the mouth and small intestine

role of protease enzyme (add example)

EG PEPSIN AND TRYPSIN, breaks down protein into amino acids, made in the pancreas and stomach but works in the stomach and small intestine

role of lipase enzyme

breaks down lipids (fats and oils) into fstty acids and glycerols, enzyme made in the pancreas but works in the small intestine

shape of fit for subrstraes and enzymes

substrate and enzymes are complimentary shape

lock and key theory

enzymes have a site called the active site which has a complimentary shape to the substrate (reactant), therefore enzymes are specific to certain substrates and therefore reactions

what does enzymes changing in shape mean

active sites changing shape

what does it mean by denatured enzyme

it loses its specific three-dimensional shape, particularly its active site, causing it to become unable to bind to its substrate and catalyze its reaction

four factors that affect enzyme activity

concentration of enzyme, concentration of substrate, temperature and ph level

CONCENTRATION OF ENZYME

initially, the rate of reaction increase bc there are more enzymes to form enzyme-substrate complex, so they are colliding successfully with substrates more often. After a certain point, the substrate concentration becomes a ‘limiting factor; as all substances are already in a. enzyme-substrate complex

CONCENTRATION OF SUBSTRATE

initially, the rate of reaction increase because there are more substrates to form a enzyme-substrate complex (ESC) so they are colliding succesfully with enzymes more often. After that, the enzyme concentration becomes a ‘limiting factor’

TEMP

initially, increasing the temp increases the rate of reaction as particles gain kinetic energy and move faster, and collide successfully forming enzyme-substrate complexes more often. After the optimum temp, the rate of reaction falls as the enzyme denatures meaning the active site changes the shape and ESC

PH

the further from the optimum PH, bonds in the active site are disrupted and the enzyme starts to denature, so there are less successful Collins, so less ESCs

CORE PRACTICAL STEPS: PH AND ENZYME

1. iodine in every dimple

2. 2cm cubed amylase, 1cm cubed chosen Ph squared

3. add 2cm squared starch

4. after 20s drop every 20s

how to improve ph and enzyme practical

could improve by dropping by 10 seconds

what is iodine

iodine is a indicator solution (yellow/orange) added to identify if starch is present, if starch is present, the solution will turn blue/black.

what is mitosis

a type of cell division that produces 2 identical daughter cells from one parent cell - daughter cells are identical to eachother and the parent cell

what do we need mitosis for

growth, replace, repare, asexual reproduction (not in humans)

cell cycle

mitosis(nucleus divides), cytokinesis (cell divides), interphase (doubles it DNA and organelles

PMAT - profase

• chromosomes condense

• nucleus dissapears

• spindle fibres form

• nucleus membrane breaks down

PMAT - METAPHASE

• chromosomes line up along the centre of the cell

• spindle fibres attach to one copy of each chromosome

PMAT - ANAPHASE

• spindle fibres pull the identical chromosomes apart

PMAT - TELOPHASE

• chromosomes copies reach opposite ends

• nucleas membranes reform

• spindle fibres break down

what is a stem cell

unspecialised cells that can divide by mitosis to make many more of itself, it can diffientate to become a specialised cell

TYPE OF STEM CELL- embryonic

• from embryos made in fertility treatments

• considered unethical by some

• ‘pluripotent’ - can become any time of cell in the body

• would be rejected by hosts immune system

TYPE OF STEM CELLS - ADULT

found in a few places such as the BONE MARROW

therefore we call bone marrow “multipotent” stem cells (they can only differentiate specialise into a few type of cells

you can have your own adult stem cells treat you without immune rejection

where are stem cells found?

in the bone marrow and can only become blood cells

what is a chromosome

a string of DNA - 46 in normal cells

differentiation meaning

refers to the changes occurring in cells of a multicellular organism so that each different type of cell becomes specialised to peform a specific function

where is a root hair cell found

found in root of your plant, - in animals we grow by making more cells by mitosis

what are growth curves

normal growth happens along the same percentile line EG. 9th percentile = 9 percent of individuals have a lower height/mass at that gage (91 percent have a higher height/mass)

what is a nerve cell

long, covered in fatty coverage that carrires electrical impulses around the body, and many short connections that link to other neuron’s

what are muscle cells

contain contraticle proteins that shorten the cell

what is osmosis

the movement of water particles from high areas of concentration (water) to low areas of concentration through a partially permeable membrane - PASSIVE

what is active transport

the movement of particles from a. low area of concentration to a high area of concentration through a partially permeable membrane - requires energy

balanced equation for photosynthesis

6CO2 + 6H20 - 6O2 + C6H1206

factors that affect diffusion - temp

increasing the temperature, the kinetic energy of particles therefore they move faster

factors that affect diffusion - surface area of membrane

increasing the surface area means that there is more pathways through the membrane roots, therefore they will have faster diffusion

factors that affect diffusion - diffusion distance

increasing the distance means there will be slower diffusion

HEART

1. veins take blood towards heart

2. arteries take blood away from heart

3. ventricles are bottom two chambers

4. atria top two chambers

5. right side is actually left

6. thicker wall has to pump blood to whole body

7. vena cava is the vein that connects the body to the heart

8. aorta in the main artery that connects the body to the heart

9. pulmonary means to do with the lungs

FORMULA FOR CARDIAC OUTPUT

stroke volume x heart rate

thicker wall =

oxygenated

what does blood consist of

55 percent plasma(urea, water & amino acids), 45 percent cells (white blood cell, red blood cell, platelets)

body system

heart - arteries - arterioles - capillaries - venues - veins

ERYTHOCYTES - RED BLOOD CELLS

• biconcave shape

• large SA for diffusion of gases

• lasts 120 days

• contain haemoglobin (red pigment, 4 oxygen molecules can bind to each haemoglobin molecule)

• formed continuously in red bone marrow as they have no nucleus

why do plants need water

• carrying dissolved mineral ions

• keeping cells rigid (dont want to wilt)

• cooling the leaves through evaporation

• photosynthesis

haracterisitcs of root hair cells

cell wall, nucleus, vacuole, cytoplasm, cell membrane

TWO ADAPTATIONS OF ROOT HAIR CELLi

increased surface area, thin cell wall - shorter diffusion distance

what do root hair cells absorb

water and nutrients

where are plant stem cells found

meristem

root of plant cell - growth zones

1 - zone of cell division - more cells are made here

2 - zone of cell elongation - cells get longer

3 - zone of cell differentiation - cells become specialised here

ROOT cap : protects the root as it moves through the soil

anaerobic respiration formula

glucose - lactic acid

aerobic respiration in animal formula

glucose and oxygen - carbon dioxide + water

anaerobic respiration in plants and yeast

glucose - ethanol ( used in beer and wine) + carbon dioxide (makes bread rise)

what is fermentation

Aerobic repirstion in plants and microorganisms

every cell with mitochondria will?

respire and will do so continuously

prokaryote

no nucleus

eukaryote

has a nucleus

diff