Foundations - Cell Biology

Plasma membrane

selectively permeable fluid structure that controls what and how much enters/leaves the cell.

Glycerol, Phosphate group

What is contained within the hydrophilic part of the phospholipid.

Cytoplasm

everything outside of the nucleus of a membrane bound cell, including organelles suspended in cytosol.

Cytosol

fluid portion of the cytoplasm that is semi-solid in consistency due to cytoskeleton proteins and dissolved material.

Nuclear envelope

casing that consists of 2 phospholipid bilayers around the nucleoplasm.

Chromatin

complex for organisation of DNA with histones and other structural proteins.

Histones

proteins that provide a base for DNA to wrap around, forming nucleosomes.

Nucleosomes

unit of histones and DNA that coil into chromatin fibres.

Nucleolus

concentrated, non-membrane-bound region of RNA and proteins in the nucleus responsible for ribosome synthesis and assembly.

Mitochondria

convert energy in food to usable energy (ATP) via cellular respiration.

Intermembrane space

space in the mitochondria between the outer and inner membranes.

Cristae

each of the partial partitions in a mitochondrion formed by infolding of the inner membrane.

Muscle cells

What cell/s will have many mitochondria due to high energy needs?

Mitochondria

convert energy in food to usable energy (ATP) via cellular respiration.

Ribosomes

organelles composed of 2 subunits that synthesise proteins.

Transport

type of vesicle moving material like proteins.

Secretory

type of vesicle used in exocytosis to dispel waste.

Extracellular

type of vesicle that leaves cell, facilitating cell-cell communication.

Peroxisome

type of vesicle containing enzymes for many metabolic reactions, including energy metabolism.

Reactive oxygen species

What damaging products do peroxisomes commonly produce and neutralise from oxidation reactions?

Kidney, liver cells

Due to their ability to detoxify substances, in what cells are peroxisomes abundant?

Lysosomes

membrane-bound sacs containing enzymes for digestion of macromolecules.

Autophagy

i.e. self digestion, lysosome breaks down damaged organelles and proteins to make space and recycle usable parts.

Centrosome

structure composed of a mother and daughter centriole needed to pull replicated chromosomes to opposite ends of the cell in division.

Centriole

composed of 9 set of microtubule triplets made of tubulin.

Endomembrane system

group of membranes and organelles that modify, package, and transport lipids and proteins.

Nuclear envelope, ER, Golgi apparatus, vesicles, plasma membrane

List 5 components of the endomembrane system.

Rough ER

interconnected sacs and tubes of membrane into which proteins are released from the ribosomes.

Structural modification

occurs to proteins in the rough ER, can involve folding and the addition of side chains.

Incorporation, secretion

What are the 2 outcomes for proteins after structural modification in the rough ER?

Smooth ER

tubular structure continuous with the RER with a range of functions.

Synthesis, carb and steroid metabolism, detoxification, stores Ca+

What are the 4 functions of the smooth ER?

Lipids, phospholipids, steroids

What are 3 products synthesised in the smooth ER?

Golgi apparatus

multiple membrane-enclosed sacs that modifies and transports molecules to their destination.

Cis golgi network

receiving side of the golgi body near the endoplasmic reticulum.

Trans golgi network

side of the golgi body that excretes finished products near the plasma membrane.

Cisternae

are flattened, membrane-bound sacs that the Golgi apparatus and ER are composed of.

Cytoskeleton

gives cytoplasm structure, governs internal cell organisation, continually reorganised - dynamic.

Microtubules

long, hollow, tubulin cylinders that acts as tracks for the transport of materials around the cell.

Microtubules, intermediate filaments, microfilaments

List the 3 components of the cytoskeleton from largest to smallest.

Intermediate filaments

flexible, rope-like structures that give the cell mechanical strength and protect the cell from stretching pressure.

Microfilaments

think, short, flexible actin fibres needed for cell movement, such as macrophages engulfing material.

Information storage, stability, reproducibility

What are 3 essential characteristics of DNA?

DNA (deoxyribonucleic acid)

molecule that stores genetic information in cells.

Nucleotide

repeating units of phosphate group, deoxyribose sugar, and nitrogenous base, from which DNA is comprised of.

Purines (AG)

Nitrogenous bases with 2 carbon rings.

Pyrimidines (UC)

Nitrogenous bases with 1 carbon ring.

Phosphodiester bond

bond linking the sugar-phosphate backbone.

46

How many chromosomes are present in somatic cells?

23

How many chromosome pairs are present in somatic cells?

23

How many chromosomes are present in germline cells.

Autosomes

describes the 1st to 22nd chromosome.

Sex chromosomes

describes the 23rd chromosome.

Genome

the complete set of genetic material in an organism, including in the mitochondria for humans.

DNA double helix, nucleosome, chromatin, chromosomes

What are the 4 levels of organisational hierarchy for DNA?

Information storage

characteristic of DNA where the sequence of bases determines amino acid order in proteins via the universal genetic code.

Stability

characteristic of DNA resulting from strong bonds within a double-stranded helical structure.

Reproducibility

characteristic of DNA enabled by using complementary base pairing to create semi-conserved strands of DNA.

Coding DNA

DNA that determines the order of amino acids in proteins making up only 2% of the human genome.

Functional RNAs, regulatory molecules

Other than proteins, what can the coding DNA code for?

Noncoding DNA

makes up most of the genome, some of which has regulatory roles (controls gene expression).

Central Dogma

genetic information flows in one direction DNA → RNA → Protein.

Transcription

occurs in the nucleus, DNA sequence copied to mRNA.

Translation

occurs in the cytoplasm, at ribosomes.