Y10 Biology Revision

Final Exam - Life Processes

Mitochondrion

Organelle where aerobic respiration occurs to produce ATP

Plasma membrane

Controls the entry and exit of substances in cells

Plasmid

Additional chromosome in bacteria that carries genes that are not essential for survival; not in all bacteria

Flagellum

Organelle responsible for locomotion

Cell Wall

Provides structural support and protection

Ribosomes

Site of synthesis of proteins that remain in cell

Rough endoplasmic reticulum

Site of synthesis of proteins that exit the cell

Golgi apparatus

Organelles that modify proteins before exocytosis

Lysosome

Organelle that contains digestive enzymes that breakdown unwanted substances in the cell

Vesicle

Small sac that connects the RER, SER, Golgi, and plasma membrane

Vacuole

Organelle that stores materials such as water, salts, proteins, and carbohydrates; predominantly in plant cells

Pili

Appendages that allow bacteria to attach to each other (and to transfer DNA)

Capsule

A layer that surrounds bacterial cell walls that protect it from antimicrobial agents

Nucleoid

Region in bacteria that contains a circular piece of DNA

Nucleus

A part of the cell containing DNA and controls cellular functions and processes

Cytoplasm

Site of chemical reactions in cells

Simple diffusion

The movement of substances down its own concentration gradient

Osmosis

The diffusion of water down its concentration gradient through a semi-permeable membrane

Active transport

The use of ATP and a protein to move substances agains the concentration gradient

Semi-permeable

Characteristic of a cell membrane which allows some molecules to pass through but not others

Concentration gradient

A difference in the concentration of a substance across a distance.

Hypertonic

When comparing two solutions, the solution with the greater concentration of solutes

Hypotonic

When comparing two solutions, the solution with the lesser concentration of solutes

Isotonic

When the concentration of two solutions is the same

Flaccid

A term used to describe plant cells that are plasmolyzed

Plasmolyzed

A state in plant cells where the plasma membrane has shrunken; occurs when cells are placed in hypertonic solutions

Turgid

A term used to describe plant cells that are swollen with water and hard; occurs when cells are placed in hypotonic solutions

Endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane

Exocytosis

release of substances out a cell by the fusion of a vesicle with the membrane.

Facilitated diffusion/transport

Movement of specific molecules across membranes through protein channels down a concentration gradient

Starch

Insoluble storage molecule for glucose in plants

Stomata

A pore on the underside of leaves of terrestrial plants that allow exchange of gases

Guard cells

Specialised cells that control the opening and closing of stomata

Chlorophyll

Pigment that absorbs light energy found in chloroplasts

Limiting factor

In photosynthesis, a resource in the shortest supply that determines its rate

Iodine

Substance that changes to a dark blue/black in the presence of starch

Stem

Facilitates transport of substances between organs in a plant

Vascular bundle

Transport system in plants made up of xylem and phloem

Xylem

Vessel that helps transport water and minerals up a plant

Phloem

Vessel that helps transport nutrients (hormones, sucrose, etc.) between organs in a plant

Aerobic respiration

The breakdown of glucose into ATP using oxygen

Alcohol fermentation

Anaerobic breakdown of glucose into ethanol and carbon dioxide and ATP

Lactic acid fermentation

Anaerobic breakdown of glucose that produces ATP and lactate

Anaerobic respiration

The breakdown of glucose in the absence of oxygen

Stem

The main structural support, facilitates transport of water, minerals, and nutrients using the vascular bundle (xylem and phloem)

Flower

Site of reproduction in plants

Roots

**Site of water and mineral absorption**. For some plants, it can also be the site of starch storage (i.e. potatoes)

Leaf

Site of photosynthesis where chlorophyll in chloroplasts absorb sunlight.

Stomata on the underside of leaves is the site of transpiration and exchange of O2 and CO2 for respiration and photosynthesis