comp 2

cells and organelles, body tissues

List the functions of a cell (4 marks)

• to metabolise and produce energy

• to synthesise molecules

• communicate with other cells and surrounding environment

• to divide, reproduce and pass genetic information

Draw the plasma membrane and label its structural components. What are three functions it possesses?

• phospholipid bilayer (hydrophilic and hydrophobic), cholesterol (45-50%), carbs (4-8%), proteins (45-50%), glycocalyx

• encloses intracellular content

• controls and regulates substances moving in/out of cell

• establishes resting membrane potential

Organelles suspend within cytoplasm. What does cytoplasm also contain and describe what this includes

• cytosol - fluid mixture of ions and proteins with water

• contains cytoplasmic inclusions: microtubules, microfilaments, intermediate-filaments

Draw a simple diagram of the nucleus, including all of its components (4). What is its main function? (2 marks)

• controls movement and activity within cell

• carries the code for structural and functional characteristics for cell

Ribosomes are produced by the nucleolus. What does it do?

site of protein synthesis, combines amino acids into chains of protein

Draw the cell and all of its main organelles

The endoplasmic reticulum (ER) can be rough or smooth, differentiate between the function of the two.

• rough ER - joins amino acids together to form proteins; synthesises and modifies proteins

• smooth ER - site of lipid, steroid and carb synthesis, detoxifies harmful substances

Draw the golgi apparatus with its cisternae and secretory vesicles. What is its main function?

modifies, packages and distributes proteins and lipids from rough ER for secretion via lysosomes

What is the function of lysosomes?

contains enzymes which breaks down wastes within cell

What is the function of centrioles?

cell division

Mitochondria consists of two structures: the outer and inner membrane, and a matrix in between. What is the purpose of mitochondria?

mainly produces and supplies ATP

What’s the difference between cilia, microvilli, flagella

• cilia: large extensions, moves substances across surface of cell

• microvilli: smaller extensions, increases surface area

• flagella: one long projection, enables motility

What is the purpose of cytoskeleton and how does it differ from cytosol

• cytoskeleton: moves organelles and changes cell’s shape

• cytosol: fluid portion of cytoplasm with a mixture of ions and proteins

histology

the study of tissues

Epithelial tissue are able to regenerate, are avascular but innervated. It’s purpose is to cover and protect structures, but what are the characteristics that it is made of? Draw a diagram

free surface, basal layer, lateral surface

Simple squamous epithelium is a single layer of flattened cells. What does it allow and where is it commonly found?

• diffusion, filtration

• alveoli, nephron serous membrane of pleura (lungs)

Simple cuboidal epithelium are cubed-shaped and some can have microvilli/cilia. This type of epithelium can be found in kidney tubules and terminal bronchioles, therefore what is its function?

absorption, secretion, movement

Simple columnar has a lot of cellular material, therefore cellular activity. As it allows absorption and secretion, where may it be found?

small intestines, stomach, digestive tract, lungs

Transitional epithelium can change in shape depending on the amount of fluid it holds. Where is this type of epithelium typically found?

bladder, ureter, upper part of urethra

Stratified squamous protects against abrasive due to its multiple layers. What are the two types and how are they different?

• keratinised: waterproofing, eg. skin

• non-keratinised: prone to abrasion, eg. vaginal canal

Stratified cuboidal is very rare and secretory, only found in ___ and ___

sweat ducts and salivary glands

Stratified columnar is a rare tissue type only found in ___ and ___

• mammary gland ducts

• larynx

Pseudo-stratified columnar are found in mostly the respiratory system, such as pharynx and trachea. What are its functions?

secretion and movement

What are the main characteristics of connective tissue?

few cells and lots of extracellular matrix (ground substance and fibres)

Describe three functions of connective tissue

transports, connects and binds together, supportive, provides energy

CT cells, ground substance and fibres are apart of CT composition. List the different types of connective tissue cells.

adipocytes, fibroblasts, mast cells, white blood cells (leucocytes), macrophages

CT cells, ground substance and fibres are apart of CT composition. What is the ground substance of CT?

fills space in between CT cells and where fibre is suspended

CT cells, ground substance and fibres are apart of CT composition. Differentiate between the 3 types of fibres

• collagen fibres - rigid and strength

• elastic fibres - stretches and recoils

• reticular fibres - thin and supportive network