Unit 1-Cell structure and Cell membranes Flashcards
What is the site of aerobic respiration (stage 2)?
Mitochondria [P;A;F]
What is the function of the Cell Wall?
Supports, Protects and maintains the shape of the cell. [P;F;B]
Site of photosynthesis?
Chloroplasts [some P]
Function of the Cell membrane?
Controls entry and exit of substances. [ALL]
Function of the sap vacuole?
Stores water,sugars and salts. [P]
Function of the Nucleus?
Controls the activities of the cell and contains genetic material DNA. [P;A;F]
What is the site of protein synthesis?
Ribosomes [ALL]
Function of plasmids?
Code for the synthesis of a few proteins not coded for by the nucleus. [B]
Why do Bacterial Cells not actually have a “true” nucleus?
A true nucleus is one that is surrounded by a membrane. Bacterial cells have no membrane surrounded organelles.
What is the cell membrane is composed of?
⚫️Lipids [fat molecules]
⚫️Proteins
Describe the composition of the cell membrane.
The lipids from a constantly moving (fluid) double layer. Some protein molecules cross the membrane others are found only on one side or other. PHOSPHOLIPID BILAYER!
What is passive transport?
Movement of substances/molecules across the membrane which does not require energy and is down a concentration gradient.
HIGH CONCENTRATION ➡️
LOW CONCENTRATION
What is diffusion?
Diffusion is an example of passive transport.
Movement of molecules or ions from high concentration to low concentration. HIGH➡️LOW
Why is diffusion important?
It allows raw materials to enter a cell and waste materials to leave.
Examples of diffusion in organisms.
⚫️ Oxygen moving from alveolus [part of lung] into a blood capillary in the lung.
⚫️A plant leaf cell taking up carbon dioxide from the internal air space for photosynthesis.
