Biology Part one: BASIC BIOLOGY

BASIC BIOLOGY

Ribosomes

Small round structures that can be attached to the E.R or free-floating in the cell, produced by the nucleolus

It makes many proteins for the cell

when an animal cell shrives, what is it called?

crenation

when a cell self destructs what is it called?

apoptosis

Cytoplasm

Jelly-like liquid that all the organelles are suspended in and allows chemicals to move around

Found in every space in the cell where there is not a organelle

Cell Membrane

Semipermeable (controls what goes in and out)

Outermost part of an animal cell (the second outermost of the plant cell)

A little line surrounding the entire cell

Nucleus

The control centre of the cell than regulates all the cell activities and contains Chromatin (compressed DNA )

a large circle found often in the center of the cell

Nucleolus

Inside of the nucleus, produced ribosomes

A small circle found in a larger circle ( in the bigger circle)

Nuclear membrane

Controls what goes in and out of the nucleus (gets broken apart during prophase)

A ring that surrounds the nucleus

Mitochondria

Produces energy, (using food and oxygen) with cellular respiration

Oval-shaped with wiggly lines in the centre

Endoplasmic Reticulum (E.R)

Work to produce materials and send it out and transporting system

Rough e.r with ribosomes attached: Produces proteins

Smooth e.r with no ribosomes attached: Produced fats in liver, detoxified drugs and alcohol

Tests and ovaries: produce testosterone and estrogen

Golgi bodies/Golgi apparatus

Stacked curve sacs

Takes what the E.R produces (proteins and lipid) and sends them off in vesicles

Vesicles:

Little small balls that act like packages for what the Golgi body send out

Vacuoles:

Store waste products and otehr things IN ONLY ANIMAL CELLS

Cytoskeleton

Internal support structure, organelle structuring, allows for the vesicle movement

Microtubules

25 nm diameter

Proteins form hollow tubes

Maintain cell and organelle shape

Help cell division (the centriole forms spindle fibres for prophase, microtubules help produce the spindle fibres)

Intermediate filaments

10 nm in diameter

Proteins coiled together into cables

Maintain the shape of the cell and some organelles

Helps the nucleus be supported and held in shape

Microfilaments

8 nm in diameter

Two strands wounded together

Maintain cell shape

these microfilaments produce the cleavage furrow during cytokinesis

Cell wall

ONLY FOUND IN PLANT CELLS

Tough material (cellulose) that surrounds the cell membrane (the outermost part of a plant cell)

Large Vacuoles

ONLY FOUND IN PLANT CELLS

store food (often starch)

store water to maintain fluid pressure (allows plant cell to stay straight up)

when the vacuole doesn’t have enough water in it, plants look wilted

chloroplast

ONLY FOUND IN PLANT CELLS

Contains green pigments called chlorophyll

Allow photosynthesis to occur to make starch for the plant

lysosomes

contains enzymes (break down waste and destroy bacteria) (ONLY FOUND IN ANIMAL CELLS)

centrioles

Produces rope like structures (spindle fibers) for mitosis

What is the fluid inside a cell called?

Intra-cellular fluid (ICF)

Aka cytoplasm

what is the fluid found around cells and capillaries

Interstitial fluid (IF)

What is the fluid found in capillaries called?

Extra cellular fluid (ECF)

What is the cell membrane made of?

Phospholipid bilayer

What is the phospholipid bilayer?

It has a head that made of phosphate (hydrophilic)

A tail that is made of lipids (hydrophobic)

there are two layers of phospholipids where the tails face each other, one layer itself is called a leaflet '

both layers are called a bilayers

phospholipids switch place in their leaflet, helps fix tears

How does double bonds affect the fluidity of the bilayer?

if the fats in the tails made double bonds instead of one bond, then it can cause kinks that take up more space, less tightly wound up, increases fluidity

Why is it bad if a bilayer is too fluid or not fluid enough?

if not fluid enough, not enough resources are entering the cells and it becomes too regulated

if too fluid, too many things enter the cell, not regulated enough

How does tail length affect the fluidity of the bilayer?

• if tail longer than 16-18 carbon atoms long, fluidity can be reduced as tails gets stuck between leaflets

How does temperature affect the fluidity of the bilayer?

High - too fluid, not a good barrier

Low - too rigid, not enough things are entering and can solidify like that, causing the cell to die

how does Cholesterol effect the fluidity of the bilayer

depends on temp:

high and normal temp: cholesterol holds lipid tails together to decrease the fluidity that high temp causes

low temps: cholesterol lets go of lipid tails to increase fluidity (combats the low temps that decreases fluidity)

Passive transport overall:

• follows the concentration gradient (only happens when things move from places of high concentration to places of low concentration, like oxygen-rich air to CO2 blood)

  • the logic behind it is that it’s easier and requires less energy to move something into a space that stuffs more of something to a packed place

• doesn’t require ATP
  

What are solutes and solvants?

solutes - things in the body, sugar, oxygen, solid things

Solvents - body fluids, blood or ECF

What is diffusion:

Movement of solutes with the concentration gradient, until both side have an equal amount of the solute

Osmosis

Water going from a place with low solutes (and high water) to an area with low water and high solutes '

When does osmosis occur?

when solutes are too large to move across the bilayer, causing water to come in and dilute the side with more solute and less water, until both sides are equal

WHat is passive transport?

• normal diffusion with the help of proteins found in the cell membrane

Are the proteins located in the cell membrane hydrophobic or hydrophilic (carriers and channels

• Hydrophobic outside to not disturb the hydrophobic tails

• Hydrophilic on the inside, to encourage molecules to pass through it

What is the first type of protein found in the cell membrane?

Channel protein:

Always open (unless closed due to signals)\

brings in large molecules and ions (often charged)

What is the first type of protein found in the cell membrane?

Carrier proteins:

not always opens

binds and takers the shape of what they are transporting, opens (like a clam) on one side of the wall to the other side

How does osmosis impact cell structure?

When a solute can’t move across the cell membrane, we rely on water to make up fro the difference

What is a isotonic solution?

the concentration of the solute is equal on both sides

no net movement (the same amount of water is leaving and entering the cell)

cells shape and condition do not change

hypotonic solution?

the concentration of the solute is too concentrated on the inside of the cell, this causes more water to come into the cell to balance everything

• overall, more cell is entering the cell than leaving the cell

how is a hypotonic solution different in animal cells and plant cells

in animal cells, the cell will burst if it stays in that condition for a long time (CALLED LYSIS)

in a plant cell, the water goes to the large vacuole and pushes the cell membrane against the cell wall

this pressure keeps the cell firm and is (CALLED TURGOR PRESSURE)

hypertonic solution?

the concentration of the solute is greater outside the cell, this causes water in the cell to move out, to balance everything

there is more water going out then in

How is hypertonic solution different in animal cells vs plant cells

Animal cells: cell shrivels (CALLED CRENATION)

plant cells: the organelles arent being pushed and the TURGOR PRESSURE is gone

How can relative concentration affect the rate of diffusion?

The bigger the difference on both sides, the faster diffusion

How can size affect the rate of diffusion?

the bigger the molecule, the harder it is to diffuse it

How can polarity affect the rate of diffusion?

A small polar molecule, can pass the membrane, through the bilayer

a large molecule cannot pass through, as the membrane is not polar

How can temperature affect the rate of diffusion?

the higher the temp, the faster diffusion as movement is speed up

How can high pressure affect the rate of diffusion?

High pressure forces molecules cross the membrane, therefore increasing the rate of diffusion

DNA is condensed into what? Why is it condensed?

• DNA is very long and is condensed into a structure called chromosomes

• it also protects the DNA and keeps it safe

How many chromosomes does a human cells have?

46 chromazones (half from one parent each)

is DNA the same in every single cell for one person?

yes, the DNA in your stomach cell is the same as the DNA in your nerve cell

Are mutations always serious?

Not always, if a mutation occurs in a sperms or egg cells, then the child will inherit the mutation

Why does cell division happen?

for growth, reproduction, repair and healing, and replacing old dead cells

what are pros and cons of both types of reproduction

asexual:

pros: produces a offspring with only one parents and very quick process

cons: offspring is genetically identical to the parent there is no gene diversity

sexual:

pros: offspring has both parents genetic info (gene diversity)

cons: slow reproduction, energy wasting

what are two types of cells:

gametes: eggs and sperm cells

somatic cells: all other body cellsv

What is the first stage of the cell cycle?

Interphase 0 where cells spend 90% of the cell cycle

the first stage of interphase

growth 1 (G1): cell grows and become very large to help prepare to divide in half

chromosome have been unwound for duplication (unwound chromosome called CHROMATIN)

second phase of interphase

synthesis (S phase)

chromatin has been duplicated, to sister chromatids

last stage of interphase

growth 2 (G2)

cell get noticeably bigger, gets ready to divide

• the cell need to duplicate a cell of its original cell size, meaning the cell must first duplicate to do this

What is stage 2 of the cell cycle?

mitosis (PMAT)

prophase, metaphase, anaphase, and telophase

first stage of mitosis

prophase:

CHROMAZONES FINALLY BECOME VISIBLE

nuclear membrane, where the chromosomes are held starts to dissolve

centrioles goes to opposite sides of the cell and shoots out spindle fibres

second stage of mitosis

metaphase (middle)

the chromosomes line up in the middle of the cell, (nuclear membrane gone by now)

the spindle fibres attached to a centromere (centre of a chromosome) (one from the left and one from the right, so that sister chromatids can be seperated)

Third stage of mitosis

Anaphase (away)

sister chromatids are divided by the spindles fibres that are now pulling back, toward the centriole, centromere splits in half and goes both ways

Last stage of the mitosis

telophase and cytokinesis happen at the same time

the sister chromatids have official split apart

New nuclear membranes are now forming around the separated chromosomes

last stage of the cell cycle

cytokinesis: where the cell divides

in animal cells: a cleavage furrow is developed in the middle of where the two cells are dividing and pinches the cell causes them to separate

plant cells: a cell plate forms in the centre of the cells, sort of the cutting them away from each other, as a plant cell is to ridge to be pinched by a cleavage furrow)

What are checkpoints in the cell cycle?

Between the stages of interphase and mitosis, specialized proteins monitor the cells’ activities and surround cells (at specific points)

these proteins send a message to the nucleus, telling it if the rest of the cell should continue with the cell cycle and division or not

Why might proteins at checkpoints of the cell cycle refuse to tell the nucleus to divide?

• Signals from surrounding cells tell the cell not to divide, not enough energy/nutrients for cell division, and DNA hasn’t been replicated properly

• DNA is damaged

  • if not severe, then the cell cycle is stopped, DNA is fixed and the cycle continues

  • If severe, then the cell will self-destruct (CALLED APOPTOSIS)

What is cancer?

a disease caused when checkpoints in the cell cycle fail

Mutation can cause uncontrolled cell division and results in too many cells in one place (a tumour)

some tumours are cancerous and result in cancer

What are the 3 things that can cause cancer

genetic: when gametes pass down mutations, cancer can also be passed down

Environmental: some mutations develop due to poor lifestyles, viruses or interactions with other toxins

a mix of both: people can inherit mutations that increase chances of cancer, which are then triggered by environmental causes

what are the two types of tumor?

benign tumour: a mass of cells that increases for no function that does not affect surrounding cells

Malignant tumour: a mass of cells that increases for no function and destroys surrounding tissues and disrupts enzymes and hormones production

What is metastasis?Why is it dangerous?

when cancer cells break away from the original tumour and move to another part of the body, they may settle and start dividing and forming a second tumour

Metastasis is dangerous as different tumours can spread and grow to different parts of the body

How to avoid cancer?

• avoid tobacco smoke, as it has chemicals that damage DNA and causes tumours

• Eat healthy and work out

• antioxidants in fruits and vegetable reduce your risk of some cancers

Cancer screening for everyone:

is important, defiantly if your family has a history of certain cancers, alternative is a genetic screening, (shows if you have DNA that is linked to certain types of cancer)

If all cells have the same DNA, then why do different cells look different?

cells function and shape are different due to some gene expressed and some and not expressed

what are the different regions of DNA

regions of DNA that have control over genetics and activities are called EXONS

regions of DNA that have no control over genetics are called INTRONS

Why is cell differential important?

It allows different cells to have their shape fit their function

What is a stem cell?

Do not have specific task/not specialized yet, but can be turned into a specialized cell, (bland or stater off cells)

What is an embryonic stem cell:

Comes from embryos (baby in wombs), can be turned into any kind of cell (this is called pluripotent)

Once a baby is born, these cells no longer exist

What is a tissue stem cell

Found in speclspecializedized cell

Limited, it can only be turned into some other cell type (called multipotent)

what is a induced pluripotent stem cells (IPL)

Adult cells that can be manipulated in a lab to be changed into another type of specialized cell, can help with organ tissue transplantation

goblet cells

has glads that produce of the mucus in our nose (gets the passage warm, traps dirt)

cilia cells:

sweeps up the dirt and bacteria that has been trapped by mucus towards mouth or nose for removal

sperm cells:

Flagellum help with movement

head is aerodynamic

egg cells

the egg has proves and ridges in it that helps the sperm land and inseminate the egg

fat cells

large vacuole that stores the fat

cushions and insulates the body

production of some hormomes

Inner ear hair cells

Flexible and tubular cells that are sensitive to vibration caused by sound waves

translates vibrations and sends signals to brain to interpret sound

red blood cells

circular shape helps aerodynamics

no nucleus making it lighter

helps transport o2 co2 and other substances

muscle tissue

Contractile filaments slides past one another to produce force and cause motion

healthy cells vs cancer cells

normal cells: large cytoplasm, single nucleus and nucleolus

thick chromatin

cancer cell: small cytoplasm, many nuclei and nucleoli (bigger)

thin chromatin

hypotonic

solute concentration is higher in the cell

hypertonic

solute concentration is higher outside the cell

radiation therapy to help cancer

kills cancer cells w/ionization

chemo therapy to help cancer

helps metastasized cancer

effective

also kills cells like hair and nails

surgeries to help cancer

very exact

painful recovery

doesn’t work for metastasize cancer