Biology-Unit 1-AOS 1

Characteristics of living things

Movement (self-generated), Respiraton(release energy from nutrients through aerobic respiration, Sensitivity (sense and react to stimili), Growth (increase and develop overtime) , Reproduction (producing offspring), Equilibrum (maintaining homeostasis through enviroment changes), Excretion ( Removing wastes)

Cell Theory

1. All living things are made up of cells 2.Cells are the smallest/basic units of life 3.All cells come from pre-exisiting cells

Prokaryotic cells

A group of single celled organisms with no nucleus and a circular group of DNA. (Bacteria and Archea)

Eukayotic cells

A group of single/multi-celled organisms with a nucleus and linear strands of DNA (Animals, Plants)

Charcteristics of Prokaryotic cells

-No nucleus -Circular DNA -Plamatids -No membrane-bound organelles -Unicelluar only -replicate by Binary fission

Charcteristics of Eukaryotic cells

-Have a nucleus -DNA is linear chromosones -Membrane-bound organelles -Unicelluar or multicelluar -replicate by mitosis (somatic cells) Meiosis (gametes)

Fill in the prokaryotic cell

Plasmid DNA, Cytosol, Circular DNA, Riobosome, Plasma membrane

Fill in the eukaryotic/Plantcell

Vacuole

-Mitochondrion

-Nucleus(linear DNA)

-Cytosol

-Golgi appartus

-Vesticle

-Smooth endoplastic reticulum

-Rough endoplastic reticulum

-lysosome

-Nucleous

-Cell wall

-Chloroplast

Fill in Animal Cell

-Small/broken upVacuoles

-Mitochondrion

-Nucleus

-Vesticle

-Smooth endoplastic reticulum

-Rough endoplastic reticulun

-Ribosome

-Golgi Appartus

What are not membrane bound organelles?

Ribosomes, Cell Wal, Cytoskeleton

Differences between Plant/Animal cells

1. Plant cells have a Cell wall

2. Plants cells have chloroplasts

3. Plants cells have a large central Vacuole

Organelle

Cellular structure that has a role to keep a cell working

Cytosol

Fluid that surrounds organelles inside a cell

Cytoplasm

includes the cytosol and organelles inside (not Nucleus)

Nucleus

DMO that contains cell’s DNA inside a nucleous that makes ribosomes

Ribosomes

Made of ribosomal DNA (rRNA), makes proteins (floats in cytoplasm or attaches to rought ER)

Rough endoplastic reticlum (RER)

coated in ribosomes, so it can make or modify proteins

Smooth endoplastic reticlum (SER)

Produces Lipids and no ribosomes

Golgi apparatus

Packaging, sorting and modification of proteins for use in a cell

Lysosome

Contains digestive enzymes that break down cell waste

Mitochondrion

Site of aerobic celluar respiration which produces ATP for celluar process, OWN DNA AND RIBOSOMES

Chloroplast

Does photosynthesis in plants and has their own DNA and ribosomes

Vacuole

Used for water/solute storage (maintans plant structure)

Plasma membrane

Selectively permable membrane barrier that controls what enters and leaves the shell

Cell wall

Provides structure to plants, bacterial and fungal cells

Vesicles

Carries substances in or out of cell

Cytoskeleton

Keep’s cell’s shape and transporting vesicles out of cel

Photo Synthesis (opposite of Celluar respiration)

Process of converting light energy, carbon dioxide and water into glucose and oxygen

Celluar respiration (opposite of Photo synthesis)

Converts glucose into ATP

Why do large cells struggle with nutrient uptake and waste removal?

Low surface area to volume ratio, so diffusion across the membrane is less efficient

Why are small cells better at nutrient uptake and waste removal?

High surface area to volume ratio, allowing faster diffusion.

What is the Plasma membrane?

Phospholipid bilayer which separates the intracelluar enviroment from the extracelluar enviroment (semipermable, embedded with proteins, carbohydrates and cholestral

Phospholipid

type of lipid that makes up the cell membrane

-Phosphate head

-two fatty acid tails

Phosphate head

Hydrophillic part of phopholipid that is polar and faces watery inside and outside of cell.

Fatty acid tails

hydrophobic part of phospholipid that is non-poalr

Amphillic

Molecules that are hydrophillic and hydrophobic

Fill in

glycolipid • cholesterol • glycoprotein • carbohydrate • integral protein • protein channel • peripheral protein • phospholipid bilayer • transmembrane protein

Phospholipid bilayer

Two layers of phospholipids that make up the cell membrane

Function of protein in Plasma membrane

form channels and help with transport (embedded in Plasma membrane)

Intregral protein

Permanently part of membrane

Transmembrane proteins

Go all the way through the bilayer

Peripheral proteins

Temporaily attached to membrane

Carbohydrates

in chains, outside of cells to proteins and helps with recognition, signalling and adhesion

Cholesterol

A lipid that helpes maintain membrane fluidity

Passive transport

The movement of molecules through a semipermable membrane and down the concentration gradient .

Concentration gradient

The difference in solute concentration between two adjacent atoms

Diffusion

Movement of molecules from high concentration to low concentration ‘down their concentration gradient’

Explain diffusion

particles are always moving which overtime leads to an even dispersion of particles in the area

What types of molecules can freely diffuse across the plasma membrane?

-small, uncharged and hydrophobic molecules (O2 and C02)

-Non polar

What is facilitated diffusion?

type of passive transport where moleucles move through a phospholipid bilayer with the aid of a membrane protein

What goes through facilitated diffusion?

-Large molecules, polar molecules and charged molecules (ions)

-as well as non-pol and small because it is FASTER

What can molecules use for facilitated diffusion?

Protein channels and carrier proteins

-(specific to certain molecules)

-

Hypertonic solutions

The solution has a higher solute concentration than the cell. Water flows out of the cell, causing it to shrivel or shrink.

Hypotonic

The solution has a lower solute concentration than the cell. Water rushes into the cell, causing it to swell and potentially burst.

Isotonic

The solution and cell have equal solute concentrations. Water moves in and out equally, meaning the cell retains its normal size and shape.

tonicity

 a measure of the relative concentration of solutes on either side of a semipermeable membrane, described as hypertonic, hypotonic, or isotonic

Conformational change

Carrier proteins adapt for a specific molecule

-returns to og shape after transport

eg Glucose carrier only glucose

Osmosis

Diffusion of water across a semi-permable membrane from low solute concentration to high solute concentration hypotonic>hypertonic, with the cocentration gradient

Membrane is seletively permable so

many solutes like sugar cannot cross easily

-water can cross easily

-instead of sugar moving water moves

Example of osmosis

-more sugar inside the cell

-less sugar outside the cell

Inside= high solute concentration

outside= Low solute concentration.

SO water moves from low solute to high solute(dilutes the sugar until concentrations become equal)

Active transport

Movement of substances across a membrane against their concentration gradient

-requires ATP

-Uses protein pumps

What is ATP

Adenosine triphosphate

define Protein-meditated transport

type of active transport which involves using membrane proteins to move molecules across a membrane, against their concentration gradient

requires

-energy (ATP)

-membrane proteins (protein pump and carrier proteins)

Steps of protein-meditated active transport

1.Binding- Target molecule binds to protein pump

2. Conformational change-ATP is broken down

ATP> ADP+P and energy is realeased so conformational change can occur in protein pumo

3. Release- Target molecule is pushed through the protein and released on the other side of plasma mebrane

Visualise the protein-meditated process

Bulk Transport (large molecules)

Type of active transport that uses vesicles to move large molecules or groups of molecules across a membrane (cytosis)

-Exocytosis

-Endocytosis

Exocytosis (opposite of endocytosis)

-Moves large substances out of cells

1. Vesicle with secretory products is transported to the plasma membrane (vesicular transport)

2. Fusion- Vesicle membrane fuses with cell membrane

3. Release- Secretory products are released from the vesicle, outside the cell

*Adds phospholipids to membrane, then releases it’s contents outside the cell

*plasma membrane increases slightly

What is happening

-Moves large substances out of cells

1. Vesicle with secretory products is transported to the plasma membrane (vesicular transport)

2. Fusion- Vesicle membrane fuses with cell membrane

3. Release- Secretory products are released from the vesicle, outside the cell

*Adds phospholipids to membrane, then releases it’s contents outside the cell

*plasma membrane increases slightly

Visualise endocytosis

Endocytosis(bulk transport) FTB fold the bubble

moves large substances into of cell

1.Fold- plasma membrane folds inwards that fills with target molecules and extracelluar fluid

2.Trap- Target molecules become enclosed as the membrane keeps folding

3.Bud- Vesicles pinches off membrane

*If taken in large amounts cell could shrink

What is the purpose of cell replication?

1. Growth and development- organisms increase their number of cells.( Cell size stays the same)

2. Maintainence and repair-Old/damaged cells are replaced, ensuring function of organism

3. Reproduction-Single-celled organisms reproduce by making identical copies

Plasmid

circular group of DNA that is separate from chromosome

Cytokineis

Division of the cytoplasm and formation of two genetically identically daughter cells

Septum

A dividing wall formed during binary fi

Steps of binary fisson DECS

1. Orginal cell

2. DNA replicated

3. Elongation

4. Cytokinesis and formation of septum

5. Two genetically identical daughter cells

Exponetial growth

1 bacerium

20 minutes> 2

40 minutes> 4

60 minutes> 8

What is the eukaryotic cell cycle

process where a cell grows, replicates it’s DNA, and divides into two idential daughter cells

Interphase-Celluar growth and duplication of chromosomes

Mitosis-Separation of sister chromatids and the formation of two new nuclei

Cytokineis- Division of the cytoplasm and formation of two daughter cells

Queiesnt

dormant cells which can re-enter the cell cycle

Terminally differentiated

Cells that are fully specialised and can no longer enter the cell cycle

Chromatid

one half of a double-standed chromosome

Centromere

Structure which holds sister chromatids together

Chromosome

Structure composed of DNA

Interphase

G1 phase

Cells grows

-proteins are synthesised

-organelles replicate

G0 phase

-cells that not required/terminally differntiated

S phase (synthesis)

-DNA replicated

-each chromosone forms

-idential sister chromatids

G2 Phase

-Cell continues growing

-proteins produced for mitosis

-prepares for division

Somatic

body cells except reproductive cells

Mitosis

Division of the nucleus producing two identical nuclei

Phases of mitosis Pass Me A Taco

Prophase

-Chromatin condeses into chromosones

-Centrioles migrate to poles of cell

-Spindle fibres form

-Nuclear membrane breaks down

Metaphase

-Chromosomes line up at the equator

-spindle fibres attach to centromeres

Anaphase

-Sister chromatids separate to opposte poles

-Centrosomes spilt

Telophase

-Chromosomes decondense

-Two nuclear membrane form

Two nuclei are produced

Cleavage furrow

an indentation of the plasma membrane during cytokinesis

Cytokinesis-Animal cell

Cleavage furrow forms

Cell pinches in two

Cytokinesis-Plant cell

-Cell plate forms

-Develops into a new cell wall

Cell cycle check points

G1 checkpoint: checks for growth, DNA damage and nutriends

G2 checkpoint: DNA replicated correctly and resources

Metaphase checkpoint: checks that chromosomes are lined up.

Apoptosis

Controlled and regualted death of cells used to remove

-Damaged cells

-Diseased cells

-Unnesscary cells

1.Mitochondrial pathway (intrisic)

2.Death receptor Pathway (extrinsic)

Steps of Mitochondrial pathway (intrisic)

*Triggred by internal cell damage

1.Mitochondrial detect damage

2.Cytochrome C is released

3.Capase enzymes are activated

4.Apoptosis begins

2.Death receptor Pathway (extrinsic)

*Trigged by external signals

1.Death signalling molecules bind to death receptors on the cell membrane

2.Capase enzymes are activated

3.Apoptosis begins

Stages of Apoptosis DSBBP don’t squish big big pickles

*after Capases are activated

1.Digestion of cell’s contents-capases break down proteins and organelles

2.Cell shrinks

3.Membrane blebbing-Plasma membrane buldges

4.Apoptosis bodies form-Cell break into small vesicles

5.Phagocytes enguld them by phagocytosis

Necrosis

-Unregulated death

-Cell damage, causes cell to burst and inflammation

Phagocytosis

After apoptosis, phagocytes engulf and digest the free-floating apoptotic bodies by phagocytosis.

phagocyte

 a cell of the immune system responsible for engulfing and destroying harmful microorganisms and foreign material

Tumour formation

If the cell cycle is disrupted or insufficient, damaged cells can replicate exponentially, leading to the development of tumours and cancers.

Maligant tumours

-invades nearby tissue

-Can spread through blood

-Spread called metastasis