Cells, Tissues, and Regukation Topic 1,2

Which part of nucleotides form the hydrogen bonds between two strands of complementary deoxyribonucleic acid (DNA)?

The nitrogen containing base

Which of the following is the main function of mitochondria?

Synthesize ATP (adenosine and Triphosphate)

The cytoskeleton can be found in which of the following cell types?

Eukaryotes

The smooth endoplasmic reticulum is responsible for synthesis of which molecules?

Lipids, and cholesterol

Which base is only used in ribonucleic acid (RNA)?

Uracil

Proteins are composed of chains of___?

Amino acids

Which organelle is responsible for destroying cell debris, invading bacteria and malfunctioning organelles?

Lysosome

How many sites exist in a ribosome wrapped around a strand of messenger RNA (mRNA)?

 

3 - E, P and A

Deoxyribonucleic acid (DNA) encodes for which of the following biomolecules?

Protein Only

How does messenger RNA (mRNA) leave the nucleus?

By the nuclear pore

Where do ribosomes exist in the cell?

Both attached to the rough ER and free cytoplasm

Most of the plasma membrane is made of what

phospholipid bilayer

What is common to both prokaryotes and eukaryotes

Both have liquid cytosol, which fills the cell

What molecular machine is responsible for synthesising proteins from messenger RNA (mRNA)?

Ribosomes

What describes mitosis

Chromosome number is doubled so that daughter cells made by cell division have one complete set

Squamous

Flattened cells, where the nucleus takes on a more elongated shape

cuboidal

Square shaped cells where the nucleus is more round in appearance with equal cytoplasm around in on all sides

columnar

cells that are rectangular in shape with the nucleus being more oval shaped and sitting towards one end generally

Roles of the Epithelia

Protection: acts a boundary between regions that require separation

Sensory: We feel and sense temperature, touch and humidity through our external epithelia

Excretory: We release the molecules that help us regulate our temperature and signal our presence to others

Epithelia

The covering/lining of all surfaces internal and external, nothing moves into or out of body without facing this barrier

avascular: without blood

the cells determine the function

endothelium

the epithelial tissue that lines our blood vessels

apical surface

the upper free side which is exposed to surface or a cavity

basal surface

the lower attached side which faces inward toward the body

pseudo stratified epithelia layer

falsely stratified, or layered

ex. Bronchi of lungs

transitional epithelia layer

this structure is specialized to be expandable

ex. walls of bladder

Tight junctions

Water-tight and will allow any large or small molecules through

Desmosomes

“Spot welds” occur where cells face high mechanical stress, these junctions help hold cells together

Gap Junctions

These small ‘gaps’ that creates a pathway between one cell’s cytoplasm to its neighbour’s cytoplasm

made with integral proteins called connexons

only ions and small molecules can move through the gap

Inter-

between

Basement membrane

The structure that forms the epithelial boundary

Exo-

outside, outer, external

Endo-

inside, inner,internal

Exchange epithelium

thin, flat cells of this epithelium allow movement through and between cells

often a simple squamous epithelium

Transporting epithelium

Selectively move substances between a lumen and the extracellular fluid

ex. gastrointestinal tract

ciliated epithelium

Beating cilia fluid currents that sweep across the epithelial surface

most commonly found in the upper respiratory tracts as part of the mucosiliary escalator which moves dust and other particles away from the lungs

secretory epithelium

Make and release a product

can be single like goblet cells or multiple cells in an endocrine gland

protective epithelium

have many stacked layer of cells that are constantly being replaced

what our skin is made of this

thick and well suited from abrasion as the top players can be lost without compromising the underlaying structure

goblet cell

most common unicellular exocrine gland found in the gastrointestinal tract and the trachea

columnar in shape

compound

branching

alveolar

rounded, bag like

merocrine gland

release products in a controlled way via exocytosis

ex, pancreatic cells, salivary glands, most sweat glands

holocrine gland

when a cell, which has accumulated a lot of product within it, ruptures or dies in order to preform its function

ex. oil glands in skin

Collagen

comprised of especially tough protein ‘strings’

Elastic

made of eelastin

long and thin

stretch and recoil

Reticular

short and fine

made of a different type of collagen than thicker collagen bundles

areolar

most common connective tissue

all three fibres present, mostly fibroblasts with transient cells like macrophages

lots of flexible ground substance

adipose

nutrient storing ability with a lipid vacuole taking up most of the cells cytoplam

squashes the nucleus to the side cell

reticular

contains a lot of ____ fibres to form a loose scaffold of support for organs and tissues

loose connective tissue

has a high proportion of ground substance (unstructured material that fills the gaps between cells and contains fibres)

Dense connective tissue

have fibres as their most dominant element, thus they look more filled and have a more stripy appearance than the loose ct

Cartilage

lacks nerve fibres

has a firm gel like ground substance

mainly has collagen fibres

protects out skeleton from tension and compression

embedded chondroblasts make the ground substance when the cartilage is growing

chondrocytes are mature and are found in lacunae

major types of cartilage

hyaline

fibrocartilage

elastic cartilage

costal cartilage in the rib cage is made of _____ cartilage

Hyaline

roles of bone

movement

posture

protection

production of blood cells

calcium store

osteon

Single structural unit of compact bone

Hollow cylinder that has alternating rings of inorganic calcified salts with collagen fibres running in opposite directions

Lamellae

In the center of the osteon

The central canal

when bone is actively growing and not yet calcified that is done by ___

osteoblasts

connects multiple tissues and has cells in a extracellular matrix of soluble fibres in fluid

blood

Without a nucleus

Prokaryotes

surrounding cells

Plasma membrane

containing the cytoskeleton, organelles, inclusions, the cytosol

Cytoplasm

movement of water soluble substances, signalling molecules, cell-cell attachment

Primary roles of the plasma membrane

polar heads, nonpolar tails

phospholipids

selective barrier between the cytosol and the external environment

The phospholipid bilayer

large, hollow tubes made of tubulin, involved in movement and structural framework for organelles

Microtubules

provide motility, beat back and forth

cilia

provide motility, roates

flagella

smallest cytoskeletal elements,determine cell shape and control of movement of structures inside cells

Actin filaments

defined by size, provide structural support

intermediate filaments

the external network of fibres

Extracellular matrix

unstructured material that exists between cells and in the ECM

Ground substance

lamelin, adhere cells to connective tissue fibres

cell-adhesion molecules in the ECM.

sugar units linked to a protein core,these help form glycocalyx

proteoglycansin the ECM.

Ribosomes on the rough ER synthesize proteins

rough endoplasmic reticulum

Protein synthesis

Ribosomes

Metabolise and synthesis of lipids, cholesterol, enzymes which can detoxify substances

smooth endoplasmic reticulum

modify, concentrate and package proteins

Golgi apparatus

have their own DNA and manufacture their own ribosomes, ATP production

mitochondria

digest biological macromolecules

Lysosomes

degrade harmful substances, neutralise oxygen free radicals, converting these to hydrogen peroxide

Peroxisomes

Double-stranded helical molecule, provide instructions for protein synthesis

DNA

Single-stranded molecule, carries the instructions on how to make proteins

RNA

made up of nucleotides

DNA/ RNA

interphase- G1, S, G2, then mitotic phase

cell cycle

cell will grow and the DNA in the nucleus will be copied

Interphase - S phase

linked amino acids

protein

make messenger RNA

transcription

ravel into the cytoplasm carrying the instructions of the DNA it has copied

messenger RNA

an amino acid-binding site, and a codon binding site, allowing binding to complementary codons in mRNA

Transfer RNA

inked to the ribosomal proteins, to form the ribosomes that make proteins

Ribosomal RNA

it binds to a promoter -  a DNA sequence specifying start site of gene to be transcribed

Transcription initiation

RNA polymerase, unwinds the DNA template, adds complementary RNA nucleotides on DNA template and joins them together

transcription elongation

termination

Once the DNA polymerase reaches the termination signal, this causes the mRNA to be pulled off

attaches to a small ribosomal subunit that moves along the mRNA to the start codon

Translation mRNA

he large ribosomal unit attaches, forming a functional ribosome

Translation Ribosome

Anticodon of a tRNA binds to its complementary codon and adds its amino acid to the forming protein chain

Translation tRNA

New amino acids are added by other tRNAs as the ribosome moves along rRNA, until the stop codon is reached

Translation stop codon